ASoC: ti: fixup ams_delta_mute() function name

commit 059374fe ("ASoC: ti: merge .digital_mute() into .mute_stream()")
merged .digital_mute() into .mute_stream().
But it didn't rename ams_delta_digital_mute() to ams_delta_mute().
This patch fixup it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/87blizy5ts.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>