ARM: dts: EMIF and LPDDR2 device tree data for OMAP4 boards

Device tree data for the EMIF sdram controllers in OMAP4
and LPDDR2 memory devices attached to OMAP4 boards.

Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Aneesh V <aneesh@ti.com>
[santosh.shilimkar@ti.com: Rebased against 3.6-rc]
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[b-cousson@ti.com: Use label in board to access EMIF nodes]
Signed-off-by: Benoit Cousson <b-cousson@ti.com>