gpu: ion: Add API to do cache operations

Clients need to be able to do cache operations
on ION buffers in the kernel. Add API to
flush, invalidate, or invalidate and flush the
cache of an ION buffer.

Change-Id: I2b676dbe32372b3c17e4aaf39f51878b105a699c
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
diff --git a/drivers/gpu/ion/ion.c b/drivers/gpu/ion/ion.c
index 76e10c8..9b1e548 100644
--- a/drivers/gpu/ion/ion.c
+++ b/drivers/gpu/ion/ion.c
@@ -882,7 +882,7 @@
 	return ret;
 }
 
-static int ion_do_cache_op(struct ion_client *client, struct ion_handle *handle,
+int ion_do_cache_op(struct ion_client *client, struct ion_handle *handle,
 			void *uaddr, unsigned long offset, unsigned long len,
 			unsigned int cmd)
 {