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

omap_elm.h is a generic header used by OMAP ELM 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/drivers/mtd/nand/omap_gpmc.c b/drivers/mtd/nand/omap_gpmc.c
index 452e40f..881a636 100644
--- a/drivers/mtd/nand/omap_gpmc.c
+++ b/drivers/mtd/nand/omap_gpmc.c
@@ -14,7 +14,7 @@
 #include <linux/bch.h>
 #include <linux/compiler.h>
 #include <nand.h>
-#include <asm/omap_elm.h>
+#include <linux/mtd/omap_elm.h>
 
 #define BADBLOCK_MARKER_LENGTH	2
 #define SECTOR_BYTES		512