ASoC: omap-mcpdm: Remove OMAP revision check

The OMAP revision check is not needed since the watchdog bit is not in use
on 4430 ES1.0 and have no effect when we set the bit. The watchdog need to
be enabled on all other revisions.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>