arch: arm: Fix armv7 init code

Fix armv7 init code to add isb macro instead of isb function.
Fix L2 cache invalidate code as per arm manual section B2-17.
Use SCTLR (System Control Register) to enable & disable caches
instead of ACTLR (Auxiliary control Register). Replace hand
coded assembly with armv7 ISA.

Change-Id: I740757a2a812d0f70a4c170af4065b4ff14e88e3
diff --git a/arch/arm/ops.S b/arch/arm/ops.S
index 6b9d966..6daea96 100644
--- a/arch/arm/ops.S
+++ b/arch/arm/ops.S
@@ -1,6 +1,8 @@
 /*
  * Copyright (c) 2008 Travis Geiselbrecht
  *
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files
  * (the "Software"), to deal in the Software without restriction,
@@ -188,9 +190,7 @@
 /* void arch_idle(); */
 FUNCTION(arch_idle)
 #if ARM_CPU_CORTEX_A8
-	.word 0xe320f003 /* wfi */
-#elif PLATFORM_MSM7K
-	/* TODO: safely handle wfi */
+	wfi
 #elif ARM_CPU_ARM1136 || ARM_CPU_ARM926
 	mov	r0, #0
 	mcr	p15, 0, r0, c7, c0, #4