ASoC: wm1133-ev1: Remove unused driver

Since commit c93197b0 ("ARM: imx: Remove i.MX31 board files"), the
MACH_MX31ADS_WM1133_EV1 non-DT platform is no longer supported,
so get rid of its machine audio driver too.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20201110203937.25684-1-festevam@gmail.com


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