ASoC: tlv320aic32x4: Remove mclk references

commit 78f2d58a upstream.

mclk is not used by anything anymore.  Remove support for it.
All that information now comes from the clock tree.

Signed-off-by: Annaliese McDermond <nh6z@nh6z.net>
Signed-off-by: Mark Brown <broonie@kernel.org>