ASoC: SOF: IPC: fix implicit type overflow

Implicit values may have a length of 15bits (s16) so we need to declare
the proper size so we don't get undefined behaviour. This appears to be
arch and compiler dependent. This commit is to keep the headers aligned
between the firmware and kernel. UBSan discovered this bug in the
firmware.

Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20201120144025.2166023-1-kai.vehmanen@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>