This patch introduce clock property for MCLK master freq control.
Driver will set rate of MCLK master if set_sysclk is called and
changing sysclk by board driver.

[Modified slightly to apply without an earlier patch in the series due
to context diffs -- broonie]
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Link: https://lore.kernel.org/r/20190903165322.20791-2-katsuhiro@katsuster.netSigned-off-by: Mark Brown <broonie@kernel.org>