sdhci: sdhci-msm: define pm qos cpu affinity mask through DT

PM QoS request type PM_QOS_REQ_AFFINE_CORES specifies for
which CPU cores the voting will be done by the cpu affinity
mask. Define the cpu mask in the DT to be used for the voting
so it can be customized for each target.

Change-Id: Iea745e4ad60cd16fb7bf6df1b5e2447b52944e70
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>