arm64: dts: allwinner: h6: Add CPU Operating Performance Points table

Add an Operating Performance Points table for the CPU cores to
enable Dynamic Voltage & Frequency Scaling on the H6.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>