platform-drivers: msm: sps: remove dfab clock voting in SPS driver

Client drivers of SPS driver will vote for dfab clock when it is
needed and relinquish the clock when it is not needed.
SPS driver only votes for dfab clock when it configures BAM-DMA
and relinquishes the clock after that.

Change-Id: I46a03633069a30f73b5159545c21e300140c5e6e
Signed-off-by: Yan He <yanhe@codeaurora.org>