ASoC: Introduce platform driver model for dm644x, dm355

Introduce the platform driver model to get platform data for dm355 and dm644x.
Register platform driver and acquire the resources in the probe function Since
the platform specific code had been moved from machine driver to dm<soc>.c

Signed-off-by: Naresh Medisetty <naresh@ti.com>
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>