arm64: Export caching APIs

External modules may need to use caching APIs. Export the symbols
to allow their use.

Change-Id: I72a862608d37dedf0980ee2790ffb93a9de82221
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>