Both mute and mic-mute LED callbacks do almost similar tasks with just
different bits. Factor out the common code and use them from the
callbacks for simplification.
This ended up with covering the forgotten stuff, too; e.g. VREF LED
handling required the temporary power up/down that was missing for the
mute LED, or some forgotten polarity checks are added.
Convert the mute LED handling in Sigmatel/IDT codec to the new vmaster
mute helper. A point to be cautiously handled is that the value
passed to the callback is inverted; the vmaster passes "enabled"
(0 = mute), while LED classdev passes "brightness" (1 = mute).
A positive side-effect by this change is that the driver gets also the
enum controls for the mute behavior like other drivers already had.
Convert the mute LED handling in Conexant codec to the new vmaster
mute helper. A point to be cautiously handled is that the value
passed to the callback is inverted; the vmaster passes "enabled"
(0 = mute), while LED classdev passes "brightness" (1 = mute).
Also the assignment of the default vmaster hook is moved at a later
point after the mute hook is set up. This assures no nested hook.
Finally, since we enable the mute-LED kcontrols always in the helper
side, the extra vmaster_mute_enum flag set up is dropped.
Convert the mute LED handling in Realtek codec to the new vmaster mute
helper. A point to be cautiously handled is that the value passed to
the callback is inverted; the vmaster passes "enabled" (0 = mute),
while LED classdev passes "brightness" (1 = mute).
The code in Thinkpad helper is also converted. In that case, just
call the new function and remove the open-code.
