Allow hint for ctl, hwdep, timer and seq

Allow hint for ctl, hwdep, timer and seq

Like pcm and rawmidi, each object parser needs to accept the hint
component.  Now a new local function _snd_conf_generic_id() was
introduced to replace each call of "comment" and "type" field checks.

Also, the two existing identical functions for pcm and rawmidi are
removed and the new function is used commonly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>