platform: msm_shared: Add API to check if scm call is available

For download mode settings some of the scm calls are not supported and
results in failure messages in the logs which is misleading. Use the new
API to check if scm call is available before making the call.

Change-Id: I0c7c5b119c31e8be55bddd3c2ed8a3850b3ee54d
1 file changed