arm64: dts: allwinner: h6: Enable CPU opp tables for Pine H64

Enable CPU and GPU opp tables for Pine H64.

This needs to change the CPU regulator max voltage to fit
the OPP table.

Also add the ramp-delay information to avoid any out of spec
running as the regulator is slower at reaching the voltage
requested compare to the PLL reaching the frequency.

There is no such information for AXP805 but similar PMIC (AXP813)
has a DVM (Dynamic Voltage scaling Management) ramp rate equal
to 2500uV/us.

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