drivers: soc: add snapshot of scm driver

This is a snapshot of scm driver as of msm-4.4 commit <9d822a9489cceee5>
("Merge "ASoC: msm: set pointers to NULL after kfree")

CRs-Fixed: 1053664
Change-Id: I601d95e64756c6bb82a6799d259431af76edf528
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>
[psodagud: Fixed most fot the warnings and written about
QCOM_SCM in Kconfig file]
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>