drm/etnaviv: Turn etnaviv_is_model_rev() into a function

Turn the etnaviv_is_model_rev() macro into a static inline function.
Use the raw model number as a parameter instead of the chipModel_GCxxxx
defines. This reduces synchronization requirements for the generated
headers. For newer hardware, the GCxxxx names are not the correct model
names anyway. For example, model 0x8000 NPUs are called VIPNano-QI/SI(+)
by VeriSilicon.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>