drivers: qcom: rpm-smd: Remove glink and smd based rpm-smd support

Newer kernel uses rpmsg framework for communication to RPM. Modify
rpm-smd driver accordigly to use rpmsg framework. Remove support for
glink and smd.

Change-Id: I3c030aaef4ea33447802e68f67088ddb51337cbc
Signed-off-by: Raghavendra Kakarla <rkakarla@codeaurora.org>