This change adds the compatible string for rpm-smd and mpm
device nodes so that rpm-smd and mpm drivers will probe
during device boot up.
Change-Id: I8816a9e3dd8c9cef39440a1bf912d6d5f06f9f59
Signed-off-by: Raghavendra Kakarla <quic_rkakarla@quicinc.com>