ASoC: da7219: Add common clock usage for providing DAI clks

There is a need to use DA7219 as DAI clock master for other codecs
within a system, which means that the DAI clocks are required to
remain, regardless of whether the codec is actually running
playback/capture. To be able to expose control of the DAI clocking
the common clock framework has been employed.

The current implementation adds a simple clock gate for enabling
and disabling the DAI clocks, with no rate control supported
(this is still handled through standard hw_params() functions as
before). If DT is enabled then the clock is added to the OF
providers list, otherwise a clkdev lookup is used.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>