arm64: dts: imx8mm-u-boot.dtsi: use dash for node names

Some of the nodes were named using a underscore, so rectify this and
consistenly use dashes.

Signed-off-by: Patrick Wildt <patrick@blueri.se>
Reviewed-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
1 file changed