mtd: nand: omap: merge duplicate GPMC data from different arch-xx headers into common omap_gpmc.h

Each SoC platform (AM33xx, OMAP3, OMAP4, OMAP5) has its own copy of GPMC related
defines and declarations scattered in SoC platform specific header files
like include/asm/arch-xx/cpu.h
However, GPMC hardware remains same across all platforms thus this patch merges
GPMC data scattered across different arch-xx specific header files into single
header file include/asm/arch/omap_gpmc.h

Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5

Signed-off-by: Pekon Gupta <pekon@ti.com>
diff --git a/drivers/mtd/nand/omap_elm.c b/drivers/mtd/nand/omap_elm.c
index 2aa7807..64dca4f 100644
--- a/drivers/mtd/nand/omap_elm.c
+++ b/drivers/mtd/nand/omap_elm.c
@@ -16,9 +16,9 @@
 #include <common.h>
 #include <asm/io.h>
 #include <asm/errno.h>
-#include <asm/arch/cpu.h>
 #include <asm/omap_gpmc.h>
 #include <asm/omap_elm.h>
+#include <asm/arch/hardware.h>
 
 #define ELM_DEFAULT_POLY (0)