libpayload: Don't use default path for kconfig

libpayload's kconfig is totally incompatible with other kconfig versions,
today. Using other versions just doesn't work any more, so don't use the
overridable $(obj)/util/kconfig path. Choose a path that reflects the
incompatibility: $(obj)/util/lp_kconfig, instead.

This whole every-(sub)project-has-it's-own-patched-kconfig-version makes
me really, really sad :'-(

Change-Id: I964772f3323dc20aa7c1cc26a384a2fbca1dbb5e
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: http://review.coreboot.org/7061
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
drivers/spi: Add support for Micron N25Q128

Support added for Micron N25Q128 SPI flash, which has
the same manufacturer id as ST Micro. Jedec ID =
0x20 0xBB 0x18. Since existing stmicro.c only compares
the last device id byte, this flash is mistakenly
identified as M25P128, which has ID = 0x20 0x20 0x18.

To handle this situation and avoid breaking code for
existing devices, a two byte .id member is added.
New devices should be added to the beginning of the
flash table array with .idcode = STM_ID_USE_ALT_ID and
.id = the two byte jedec device id.

A 4KB subsector erase capability is added and used for
this new device. It requires using a different SPI
op-code supported by adding .op_erase member. Previous
devices defined in stmicro.c are assigned their original
op-code for 64KB sector erase.

N25Q128 is now working on a custom designed Bayley Bay
based board. Tested by verifying the MRC fastboot cache
is successfully (re)written. Note that previous devices
were not retested.

Change-Id: Ic63d86958bf8d301898a157b435f549a0dd9893c
Signed-off-by: Scott Radcliffe <sradcliffe@microind.com>
Reviewed-on: http://review.coreboot.org/7077
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)