* os_check: cm5: Check for CM5 specific dtbs
Check for BCM2712 support in bcm2712-rpi-cm5-cm5io.dtb
or bcm2712-rpi-cm5l-cm5io.dtb on CM5 instead of bcm2712-rpi-5-b.dtb.
This avoids needing to put os_check=1 or specifying device_tree
in config.txt in minimal images for CM5.
See: https://github.com/raspberrypi/rpi-eeprom/issues/682