ARM: Davinci: Remove references to davinci pcm

Since davinci-pcm is no more a platform_driver but helper to register
"platform" pcm driver, remove  davinci-pcm device registration

Signed-off-by: Hebbar, Gururaja <gururaja.hebbar@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>