ASoC: Intel: avs: Fix avs_path_module::instance_id size

ASoC: Intel: avs: Fix avs_path_module::instance_id size

[ Upstream commit 320f4d868b83a804e3a4bd61a5b7d0f1db66380e ]

All IPCs using instance_id use 8 bit value. Original commit used 16 bit
value because FW reports possible max value in 16 bit field, but in
practice FW limits the value to 8 bits.

Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20230519201711.4073845-7-amadeuszx.slawinski@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>