mmc: sdhci: Vote for PM QOS

Vote for PM QOS by specifying the acceptable CPU to DMA latency
so that system can enter into the possible power states without
affecting the SDHC performance.

Change-Id: I5fcf9aa93da690c6e64ab70ea5b039ca663c80ad
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
[xiaonian@codeaurora.org: fix trivial merge conflict]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>