davinci: ASoC: Add the platform devices for ASP

1) Registers the platform devices for ASP on dm355, dm644x and dm646x
   so that the machine driver can probe to get ASP related platform
   data.
2) Move towards definition of the asp clocks using physical name(for
   dm355 and dm644x)
3) Add platform data to board specific files.

Signed-off-by: Naresh Medisetty <naresh@ti.com>
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>