alsa: add annotations to bitwise type snd_pcm_hw_param_t

Fully half of all alsa sparse warnings are from snd_pcm_hw_param_t degrading
to integer type, this goes a long way towards eliminating them.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>