ASoC: Remove redundant -codec from WM8903 driver name

It causes noisy -codecs to appear in things like .codec_name.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>