Revert "ARM: dma-mapping: remove dmac_clean_range and dmac_inv_range"

This partially reverts commit
702b94bf
("ARM: dma-mapping: remove dmac_clean_range and dmac_inv_range")

Some MSM drivers still use the dmac_clean and
dmac_inv_range APIs. Bring back the defines and
exports for v7 CPUs.

Change-Id: I69017d73da1065a5eeb9c87c899b6a51be5ebfe6
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Abhimanyu Kapur <abhimany@codeaurora.org>