msm: sps: Handle low memory condition in SPS driver

In low memory condition some bam client is sensitive to timing
and may get time out while allocating memory through kzalloc.

Add support to hold memory during connect and disconnect
and to release memory during client driver's deregistration
of its BAM.

Change-Id: Iaf89dc542b62c95f055e7b06d788d896809b0bf8
Signed-off-by: Rama Krishna Phani A <rphani@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>