NVRAM file set's boarflags3 to 0x48200100 which indicates the firmware
that an external LPO is present. But on the RPi4 no external LPO exists.
Fixes: 870b805 ("brcm: Update Raspberry Pi 3B+/4B NVRAM for downstream changes")
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>