Add Richtek rt9120 audio amplifier support.
Signed-off-by: NChiYuan Huang <cy_huang@richtek.com>
[Fix a Gain->Volume -- broonie]
Message-Id: <1633668612-25524-3-git-send-email-u0084500@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>