dma-mapping-fast: reduce TLBI during map

Fastmap rely on minimizing tlbi to improve map performance.
At present only one marker is used to indicate if stale TLB might be used.
Instead use a clean bitmap for mapping to further reduce the TLB
invalidations.

Change-Id: I5a8dffde31f8804811357a83893b6ce0d863e8a9
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>