ARM: OMAP2+: Add function to read GPMC settings from device-tree

Adds a function to read the various GPMC chip-select settings from
device-tree and store them in the gpmc_settings structure.

Update the GPMC device-tree binding documentation to describe these
options.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Add device-tree support for NOR flash

NOR flash is not currently supported when booting with device-tree
on OMAP2+ devices. Add support to detect and configure NOR devices
when booting with device-tree.

Add documentation for the TI GPMC NOR binding.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Add additional GPMC timing parameters

Some of the GPMC timings parameters are currently missing from the GPMC
device-tree binding. Add these parameters to the binding documentation
as well as code to read them.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Convert NAND to retrieve GPMC settings from DT

When booting with device-tree, retrieve GPMC settings for NAND from
the device-tree blob. This will allow us to remove all static settings
stored in the gpmc-nand.c in the future once the migration to
device-tree is complete.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP2+: Convert ONENAND to retrieve GPMC settings from DT

When booting with device-tree, retrieve GPMC settings for ONENAND from
the device-tree blob. This will allow us to remove all static settings
stored in the gpmc-nand.c in the future once the migration to
device-tree is complete.

The user must now specify the ONENAND device width in the device-tree
binding so that the GPMC can be programmed correctly. Therefore, update
the device-tree binding documentation for ONENAND devices connected to
the GPMC to reflect this.

Please note that this does not include GPMC timings for ONENAND. The
timings are being calculated at runtime.

There is some legacy code that only enables read wait monitoring for
non-OMAP3 devices. There are no known OMAP3 device issues that prevent
this feature being enabled and so when booting with device-tree use the
wait-monitoring settings described in the device-tree blob.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: dts: Add GPMC node for OMAP2, OMAP4 and OMAP5

Add the device-tree node for GPMC on OMAP2, OMAP4 and OMAP5 devices.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: dts: Add NOR flash bindings for OMAP2420 H4

Add device-tree node for the 64MB NOR on the OMAP2420-H4 board.

The "simple-bus" string is add to the compatible property so that the
NOR device will be automatically registered with the kernel by
device-tree.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: dts: Add OMAP3430 SDP flash memory bindings

Add the device-tree nodes for the following flash devices found on the
OMAP3430 SDP board:

- 128MB NOR flash
- 128MB ONENAND flash
- 256MB NAND flash

The "simple-bus" string is add to the compatible property so that the
NOR device will be automatically registered with the kernel by
device-tree.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>