msm: idle-v7: Write to SMEM only for PC

Write to shared memory structure only when
C0 attempts to do a PC

Change-Id: Ia9c2da78c0ab2f2500b79f3172ca393038d04512
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
Merge "msm: idle-v7: Write to SMEM only for PC"