ipm: imx: Initialize variable before using it

Since the driver is passing the whole buffer, let's zero it to avoid
pass garbage in case of size != buffer's size.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
(cherry picked from commit 98857c267d5825f8b3f3fd1040b7ce222b7f3958)
1 file changed