ASoC: wm8904: Fix enum ctl accesses in a wrong type

"DRC Mode" and "EQ Mode" ctls in wm8904 codec driver are enum, while
the current driver accesses wrongly via value.integer.value[].  They
have to be via value.enumerated.item[] instead.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>