ASoC: omap-mcbsp: Configure wakeup in later phase

Configure the WAKEUPEN register at the same time we configure the rest of
the McBSP registers.
In case of OMAP3+, if the sysclock has been reconfigured we are going to
disable McBSP for the duration of the clock change, which will reset the
McBSP registers. The WAKEUPEN register need to be configured later, so
the changes will be effective during runtime.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicrocom>
Signed-off-by: Liam Girdwood <lrg@ti.com>