ASoC: intel: mfld: Fix enum ctl accesses in a wrong type

"Playback Switch" and "Lineout Mux" ctls in medfld machine 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>