arm64: dts: fsl: librem5: Add the proximity sensor

Enable the proximity/ambient light sensor on the Librem5 devkit.

Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
2 jobs for imx8-4.18-wip in 41 minutes and 24 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #10950
librem5
build:aarch64:Image

00:41:24

passed #10951
librem5
build:aarch64:deb

00:26:04