x86/mrst: Quiet sparse noise about plain integer as NULL pointer

The second parameter to intel_scu_notifier_post is a void *, not
an integer.

This quiets the sparse noise:

 arch/x86/platform/mrst/mrst.c:808:48: warning: Using plain integer as NULL pointer
 arch/x86/platform/mrst/mrst.c:817:43: warning: Using plain integer as NULL pointer

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/201204241500.53685.hartleys@visionengravers.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>