arm64: dts: imx8mq-librem5: don't set the wifi-3v3 regulator always-on

it's wired up correctly as input for vmmc-supply an it's not needed
to be configured as always-on.
2 jobs for wifi_regulator_not_always_on in 72 minutes and 13 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #370791
librem5
build:aarch64

00:20:29

passed #370792
librem5:arm64
build:deb

01:12:11