armv7: rename cache related CONFIG flags

Replace the cache related CONFIG flags with more meaningful
names. Following are the changes:

CONFIG_L2_OFF	     -> CONFIG_SYS_L2CACHE_OFF
CONFIG_SYS_NO_ICACHE -> CONFIG_SYS_ICACHE_OFF
CONFIG_SYS_NO_DCACHE -> CONFIG_SYS_DCACHE_OFF

Signed-off-by: Aneesh V <aneesh@ti.com>
V2:
 * Changed CONFIG_L2_OFF -> CONFIG_SYS_NO_L2CACHE
V4:
 * Changed all three flags to the final names suggested as above
   and accordingly changed the commit message
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S
index 3c5f3ef..200a800 100644
--- a/arch/arm/cpu/arm1136/start.S
+++ b/arch/arm/cpu/arm1136/start.S
@@ -512,10 +512,10 @@
 	.align 5
 .global arm1136_cache_flush
 arm1136_cache_flush:
-#if !defined(CONFIG_SYS_NO_ICACHE)
+#if !defined(CONFIG_SYS_ICACHE_OFF)
 		mcr	p15, 0, r1, c7, c5, 0	@ invalidate I cache
 #endif
-#if !defined(CONFIG_SYS_NO_DCACHE)
+#if !defined(CONFIG_SYS_DCACHE_OFF)
 		mcr	p15, 0, r1, c7, c14, 0	@ invalidate D cache
 #endif
 		mov	pc, lr			@ back to caller