elog: Do not attempt to init SPI

This severs a dependency the eventlog code has on initializing
chipset/SoC SPI controller. Currently elog_init() calls spi_init()
as a catch-all. This worked for x86 since the SPI controller is only
used for one thing on existing platforms. As we add eventlogging
support to non-x86 platforms we need to consider the more generalized
case where the assumptions about how SPI works on x86 are no longer
valid.

BUG=none
BRANCH=none
Signed-off-by: David Hendricks <dhendrix@chromium.org>
TEST=built and booted on Link, Beltino and Rambi. See below for
"mosys eventlog list" output on Link showing boot and suspend/resume
events (including lid close/open) added successfully.

localhost ~ # mosys eventlog list
0 | 2014-04-14 13:52:44 | Log area cleared | 4096
1 | 2014-04-14 13:52:44 | System boot | 50
2 | 2014-04-14 13:52:44 | EC Event | Power Button
3 | 2014-04-14 13:52:44 | SUS Power Fail
4 | 2014-04-14 13:52:44 | System Reset
5 | 2014-04-14 13:52:44 | ACPI Wake | S5
6 | 2014-04-14 13:53:25 | ACPI Enter | S3
7 | 2014-04-14 13:53:35 | ACPI Wake | S3
8 | 2014-04-14 13:53:35 | Wake Source | RTC Alarm | 0
9 | 2014-04-14 13:53:49 | ACPI Enter | S3
10 | 2014-04-14 13:54:00 | EC Event | Lid Open
11 | 2014-04-14 13:54:00 | ACPI Wake | S3
12 | 2014-04-14 13:54:00 | Wake Source | GPIO | 15

Original-Change-Id: I26e25c0a856f7b8db5ab6b8e7e1acae291d2eadc
Original-Reviewed-on: https://chromium-review.googlesource.com/194526
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Commit-Queue: David Hendricks <dhendrix@chromium.org>
Original-Tested-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 2971d20b6ebdd9803b05ccbbaeefe1bde1a21af4)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ia5f2913fd8e4fee6e741e6d1e39d32bb86525cb3
Reviewed-on: http://review.coreboot.org/7831
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
elog: Isolate some x86-isms

This attempts to isolate/fix some x86-isms:
- Translate flash offset to memory-mapped address only on x86.
- Guard ACPI-dependent line of code
- Use a Kconfig variable for SPI bus when probing the flash rather
  than assuming the bus is always on bus 0.
- Zero-out timestamp on non-x86 until we have a better abstraction.

(note: this is based off of some of Gabe's earlier work)

BUG=none
BRANCH=none
TEST=needs testing
Signed-off-by: David Hendricks <dhendrix@chromium.org>

Original-Change-Id: I887576d8bcabe374d8684aa5588f738b36170ef7
Original-Reviewed-on: https://chromium-review.googlesource.com/191203
Original-Commit-Queue: David Hendricks <dhendrix@chromium.org>
Original-Tested-by: David Hendricks <dhendrix@chromium.org>
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 1fc7a75f8c072098e017104788418aeed0705e93)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ida4b211cf21ecdde9745d4dbef6a63ffb9fbba8d
Reviewed-on: http://review.coreboot.org/7832
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
elog: Use the RTC driver interface instead of reading CMOS directly.

Use the RTC driver interface to find the timestamp for events instead of
reading the CMOS based RTC directly on x86 or punting on ARM. This makes
timestamps available on both architectures, assuming an RTC driver is
available.

BUG=None
TEST=Built and booted on nyan_big and link and verified that the timestamps
in the event log were accurate.
BRANCH=nyan

Original-Change-Id: Id45da53bc7ddfac8dd0978e7f2a3b8bc2c7ea753
Original-Signed-off-by: Gabe Black <gabeblack@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/197798
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Tested-by: Gabe Black <gabeblack@chromium.org>
Original-Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 493b05e06dd461532c9366fb09025efb3568a975)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I8481adde86d836b5f0b019c815bada6d232a4186
Reviewed-on: http://review.coreboot.org/7833
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>