Switch install from RPI4 to RPI5

@BRX7
See if this makes any difference. Posted on arch-arm forums:

sudo nano /etc/X11/xorg.conf.d/99-v3d.conf

Section "OutputClass"
Identifier "vc4"
MatchDriver "vc4"
Driver "modesetting"
Option "PrimaryGPU" "true"
EndSection