ARM: omap: Fix GPMC init for OMAP3 platforms

ARM: omap: Fix GPMC init for OMAP3 platforms

Commit a0a37183 (ARM: omap: merge GPMC initialization code for all
platform) broke NAND on OMAP3 based platforms. I noticed this while
testing the latest 2014.07-rc version on the TAO3530 board. NAND
detection did not work with this error message:

NAND:  nand: error: Unable to find NAND settings in GPMC Configuration - quitting

As OMAP3 configs don't set CONFIG_NAND but CONFIG_NAND_CMD. the GPMC
was not initialized for NAND at all. This patch now fixes this issue.

Tested on TAO3530 board.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Pekon Gupta <pekon@ti.com>
Cc: Tom Rini <trini@ti.com>
Acked-by: Pekon Gupta <pekon@ti.com>