arm64: dts: imx8mq-librem5: wire up the wifi regulator

Connect the wifi power regulator to the corresponding GPIO.

Signed-off-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>