ASoC: tas2770: Allow mono streams

stable inclusion
from stable-v5.10.138
commit dffe1c4780e09b6fa6c1e8e28f2b231ad2cab7ce
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=dffe1c4780e09b6fa6c1e8e28f2b231ad2cab7ce



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commit bf54d97a upstream.

The part is a mono speaker amp, but it can do downmix and switch between
left and right channel, so the right channel range is 1 to 2.

Fixes: 1a476abc ("tas2770: add tas2770 smart PA kernel driver")
Signed-off-by: Martin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220808141246.5749-3-povik+lin@cutebit.org


Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>