ASoC: ux500: Drop redundant msp id enumerations

Ux500 has two equivalent enum for device id, one in platform_data and
one in a local header.  Fix this by dropping the local one.

Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>