ALSA: hda/hdmi - enable runtime pm for newer AMD display audio

We are able to power down the GPU and audio via the GPU driver
so flag these asics as supporting runtime pm.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20191122214353.582899-4-alexander.deucher@amd.com


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