ASoC: remove unused davinci support

The dm644x and dm3xx SoCs have been removed, as have the
da850_evm/da830_evm machines, the remaining machines all use the
DT based probing and do not use the vcif driver.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>