armv7: add PL310 support to u-boot

PL310 is the L2$ controller from ARM used in many SoCs
including the Cortex-A9 based OMAP4430

Add support for some of the key PL310 operations
	- Invalidate all
	- Invalidate range
	- Flush(clean & invalidate) all
	- Flush range

Signed-off-by: Aneesh V <aneesh@ti.com>
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index f993d74..d31321a 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -40,6 +40,7 @@
 COBJS-y	+= bootm.o
 COBJS-y	+= cache.o
 COBJS-y	+= cache-cp15.o
+COBJS-$(CONFIG_SYS_L2_PL310) += cache-pl310.o
 COBJS-y	+= interrupts.o
 COBJS-y	+= reset.o
 SOBJS-$(CONFIG_USE_ARCH_MEMSET) += memset.o