ASoC: ux500: remove platform_data support

The platform data definition for ux500 sound devices was removed
six years ago after the DT conversion was completed, see commit
4b483ed0

 ("ARM: ux500: cut some platform data").

Remove some leftover bits in the ASoC driver and just assume that
it always gets probed using DT.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230118161110.521504-3-arnd@kernel.org


Signed-off-by: Mark Brown <broonie@kernel.org>