msm: ipa: add support to request/release BAM DMA clock

BAM-DMA clock will now be gated by default and clients using
it need to enable/disable it as needed. This commit adds that
support in IPA driver.

Change-Id: I583c2485607954b0c19f51e747d6b958753d8429
Signed-off-by: Ravi Gummadidala <rgummadi@codeaurora.org>