package/mesa3d: select vc4 driver for gallium v3d
Although the Gallium V3D driver for RPi4 can be built independently, in
practice the accelaration doesn't work unless the VC4 driver is also
enabled.
Select VC4 automatically when V3D is selected.
Signed-off-by: Howard Mitchell <hm@hmbedded.co.uk>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>