msm: kgsl: Verify the offset of the profiling buffer

If a command is using a profiling buffer, make sure that the offset
is within the bounds of the specified memory descriptor.

Change-Id: Ic0dedbadc77e8eccd957136467bd0c56a1af2dab
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>