dm: cache: add the pl310 cache controller driver

Add a PL310 cache controller driver that is usually found on
ARMv7(32-bit) devices. The driver configures the cache settings that can
be found in the device tree files.

This initial revision only configures basic settings(data & instruction
prefetch, shared-override, data & tag latency). I believe these are the
settings that affect performance the most. Comprehensive settings can be
done by the OS.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile
index 2ba6806..9deb961 100644
--- a/drivers/cache/Makefile
+++ b/drivers/cache/Makefile
@@ -1,3 +1,4 @@
 
 obj-$(CONFIG_CACHE) += cache-uclass.o
 obj-$(CONFIG_SANDBOX) += sandbox_cache.o
+obj-$(CONFIG_L2X0_CACHE) += cache-l2x0.o