ARM: armv7 fix spelling of SCTRL

SCTLR is the abbreviation of System Control Register, so we should
use SCTLR but not SCTRL.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
index 01cdb7e..c56417d 100644
--- a/arch/arm/cpu/armv7/cpu.c
+++ b/arch/arm/cpu/armv7/cpu.c
@@ -53,7 +53,7 @@
 	 * After D-cache is flushed and before it is disabled there may
 	 * be some new valid entries brought into the cache. We are sure
 	 * that these lines are not dirty and will not affect our execution.
-	 * (because unwinding the call-stack and setting a bit in CP15 SCTRL
+	 * (because unwinding the call-stack and setting a bit in CP15 SCTLR
 	 * is all we did during this. We have not pushed anything on to the
 	 * stack. Neither have we affected any static data)
 	 * So just invalidate the entire d-cache again to avoid coherency