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

This partially reverts commit
702b94bf. 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>