ASoC: tas2770: Add missing bias level power states

ASoC: tas2770: Add missing bias level power states

[ Upstream commit 4272caf34aa4699eca8e6e7f4a8e5ea2bde275c9 ]

Add the BIAS_STANDBY and BIAS_PREPARE to the set_bias_level or else the
driver will return -EINVAL which is not correct as they are valid
states.

Fixes: 1a476abc723e6 ("tas2770: add tas2770 smart PA kernel driver")
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200918190548.12598-2-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>