Improve AMD ACP Vangogh audio support for Steam Deck

Merge series from Cristian Ciocaltea <cristian.ciocaltea@collabora.com>:

This patch series provides several fixes and improvements to AMD ACP drivers
targeting the Vangogh platform, as found on the Valve's new Steam Deck OLED.

Although in theory the board should have been supported by both SOF and legacy
ACP drivers, as of next-20231208 the audio seems to be completely broken.

Please note this only restores the legacy support, while SOF will be handled in
a separate series.