arm64: dts: allwinner: a64: Add GPU opp table

GPU on A64 currently runs at default frequency, which is 297 MHz. This
is a bit low in some cases and noticeable lag can be observed in GPU
rendered UIs. GPU is capable to run at 432 MHz.

Add GPU OPP table.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210912095032.2397824-1-jernej.skrabec@gmail.com