arm64: provide dma cache routines with same API as 32 bit

The APIs __dma_inv_range() and __dma_clean_range() were
not exported by the third party patch. Since the functions
starting with underscores are not to be directly used by drivers,
related functions without the underscores are provided
which have the same name and functionality as the 32 bit APIs.

Change-Id: Ie0e681614307d9d9a19e58cacfb9b5dff4528977
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>