Add hw monitor volume control for POD HD500. The same change may
work for HD500X but I don't have it to test.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Link: https://lore.kernel.org/r/20200713152852.65832-1-anarsoul@gmail.com


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