dts: revpi-*: correct name of mmc activity node
requested to merge github/fork/linosanfilippo-kunbus/fix/REVPI-1837/fix_mmc_led into devel/revpi-5.10
Created by: linosanfilippo-kunbus
With commit fc71d8df the name of the node for the MMC activity LED has changed from "act" to "led-act". Adjust all revpi overlays to the new name.
Signed-off-by: Lino Sanfilippo l.sanfilippo@kunbus.com