ALSA: hda - Call snd_array_init() early and only once

This is a preliminary patch for introducing a protection to access
races of snd_array instances.  Call snd_array_init() appropriately
at the initialization time and don't call it twice.

Also the allocations of codec-spec structs are cleaned up by helper
functions in patch_sigmatel.c and patch_analog.c.

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