msm: adsprpc: Skip CPU sync during map

Do not flush the cache while mapping the dma buf. Also, update the
direction to TO_DEVICE while flushing the cache and to FROM_DEVICE
during invalidation.

Change-Id: Ifb187cfc466ff6f7859faabb424a0f38996a4192
Acked-by: Vishnu Karthik D <vikarthi@qti.qualcomm.com>
Signed-off-by: Tharun Kumar Merugu <mtharu@codeaurora.org>