mtd: nand: omap: move omap_gpmc.h from arch/arm/include/asm to drivers/mtd/nand

omap_gpmc.h is a generic header used by OMAP NAND driver for all TI platfoms.
Hence this file should be present in generic folder instead of architecture
specific include folder.
Build tested using: ./MAKEALL -s am33xx -s omap3 -s omap4 -s omap5

Signed-off-by: Pekon Gupta <pekon@ti.com>
diff --git a/arch/arm/include/asm/arch-omap3/sys_proto.h b/arch/arm/include/asm/arch-omap3/sys_proto.h
index 83d7f11..44fa66f 100644
--- a/arch/arm/include/asm/arch-omap3/sys_proto.h
+++ b/arch/arm/include/asm/arch-omap3/sys_proto.h
@@ -7,7 +7,7 @@
  */
 #ifndef _SYS_PROTO_H_
 #define _SYS_PROTO_H_
-#include <asm/omap_gpmc.h>
+#include <linux/mtd/omap_gpmc.h>
 
 typedef struct {
 	u32 mtype;