mfd: arizona: Add MICVDD to mapped regulators for wm8997

The previous update adding MICVDD to the regulator mappings:

mfd: arizona: Add MICVDD to mapped regulators

Only added the mapping for wm5102 and wm5110 but wm8997 also has a
MICVDD supply that needs to be mapped back to the main Arizona device.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>