ASoC: Remove broken WM8350 direction constants

The WM8350 driver was using some custom constants to interpret the direction
of the MCLK signal which had the opposite values to those used as standard
by the ASoC core, causing confusion in machine drivers such as the 1133-EV1
board.

Reported-by: Tommy Zhu <Tommy.Zhu@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>