mfd: arizona: Add support for INn_Mode register control

Some boards need to set the INn_MODE[1:0] register to change
the input signal patch. This wlf,inmode property is optional.
If present, values must be specified less than or equal to
the number of input singals. If values less than the number
of input signals, elements that has not been specifed are set
to 0 by default.

Example:
   - wlf,inmode = <2 0 2>;	/* IN1, IN3 use DMIC */

Signed-off-by: Inha Song <ideal.song@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>