soc: qcom: Remove couple of exported functions

Client driver should be able to call scm_call2
and need of exporting APIs for individual calls.
So remove following scm_restore_sec_cfg and
scm_get_feat_version APIs.

Change-Id: I3025319115cd950f584c34191b844434ee44b36f
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>