The speaker auto-muting per HP plugging for ALC262 HIPPO and compatible
devices is slightly buggy as the "Master" or "Front" mixer control can
still toggle the speaker output even if the headphone is plugged.

This patch fixes the issue, and clean up the hippo-related codes
together with fixes of some inconsistent mixer names.
Signed-off-by: Takashi Iwai <tiwai@suse.de>