mediatek: disable RTC on Bananapi R64 and refresh patches
The in-SoC RTC of the Bananapi R64 is more disruptive than useful
without a battery connected. Disable it to not have Linux use the
RTC provided time 2000-01-01 00:00:00 after power-loss.
Signed-off-by: Daniel Golle <[email protected]>