drm/etnaviv: add HWDB entry for GC7000 rev 6204

This is the 3D GPU found on the i.MX8MP SoC. The feature bits are
taken from the NXP downstream kernel driver 6.4.3.p1.305572.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>