ASoC: omap-mcbsp: Cleanup of module probe/remove code

Use devm_* where it is possible to save on cleanup path.
Start merging the two mcbsp file content.
Move pm_runtime_enable/disable calls to ASoC probe, remove from module
probe/remove time.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Liam Girdwood <lrg@ti.com>