pxa: add support for D- and I- caches

Tested with OHCI and pxafb drivers - no issues found

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
diff --git a/arch/arm/cpu/pxa/Makefile b/arch/arm/cpu/pxa/Makefile
index 3ee08cd..79fcb73 100644
--- a/arch/arm/cpu/pxa/Makefile
+++ b/arch/arm/cpu/pxa/Makefile
@@ -14,3 +14,4 @@
 obj-y	+= timer.o
 obj-y	+= usb.o
 obj-y	+= relocate.o
+obj-y	+= cache.o