omap2/3/4: Introducing 'gpmc-nand.c' for GPMC specific NAND init

Introducing 'gpmc-nand.c' for GPMC specific NAND init.
For example: GPMC timing parameters and all.
This patch also migrates gpmc related calls from 'nand/omap2.c'
to 'gpmc-nand.c'.

Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 492cf16..0b17dca 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -135,5 +135,8 @@
 onenand-$(CONFIG_MTD_ONENAND_OMAP2)	:= gpmc-onenand.o
 obj-y					+= $(onenand-m) $(onenand-y)
 
+nand-$(CONFIG_MTD_NAND_OMAP2)		:= gpmc-nand.o
+obj-y					+= $(nand-m) $(nand-y)
+
 smc91x-$(CONFIG_SMC91X)			:= gpmc-smc91x.o
 obj-y					+= $(smc91x-m) $(smc91x-y)