ion: Add null-pointer check to info structure

Add null-pointer check to info structure to avoid null-pointer
dereference and subsequent kernel crash.

Change-Id: I88135c1efa0b6ddc333e16511016d3618d9d5cf3
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
msm: mdss: Toggle notify state with power state