payload_size is a 12 bit field in the HW register, so add a limit for
this size. That way we gracefully reject the message beforehand instead
of generating an OOPS while transferring. Verified using some older
Tegra2 documentation and a more recent Jetson TK1 board.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>