In case of sample rates lower than 44100 currently there is too low MCLK
frequency set for the CODEC. Playback fails with following errors:

$ speaker-test -c2 -t sine -f 1500 -l2 -r 32000

Sine wave rate is 1500.0000Hz
Rate set to 32000Hz (requested 32000Hz)
Buffer size range from 128 to 131072
Period size range from 64 to 65536
Using max buffer size 131072
Periods = 4
Unable to set hw params for playback: Invalid argument
Setting of hwparams failed: Invalid argument

[  497.883700] max98090 1-0010: Invalid master clock frequency

To fix this the I2S root clock's frequency is increased, depending
on sampling rate.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>