ALSA: pcm: calculate non-mask/non-interval parameters always when possible

A structure for parameters of PCM runtime has parameters which are
not classified as mask/interval type. They are decided only when
corresponding normal parameters have unique values.
 * struct snd_pcm_hw_params.msbits
 * struct snd_pcm_hw_params.rate_num
 * struct snd_pcm_hw_params.rate_den
 * struct snd_pcm_hw_params.fifo_size

Current implementation of hw_params ioctl sometimes doesn't decide these
parameters even if corresponding parameters are fixed, because these
parameters are evaluated before a call of snd_pcm_hw_params_choose().

This commit adds a helper function to process the parameters and call it
in proper positions.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>