arm64: dts: renesas: beacon: Enable micbias

The IN3R is connected to an analog microphone, and it needs the
micbias enabled in order to power the analog microphone.

Signed-off-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/20210630175935.189454-1-aford173@gmail.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>