clk: sunxi-ng: sun6i-a31: Enable PLL-MIPI LDOs when ungating it
The PLL-MIPI clock is somewhat special as it has its own LDOs which
need to be turned on for this PLL to actually work and output a clock
signal.
Add the 2 LDO enable bits to the gate bits. This fixes issues with
the TCON not sending vblank interrupts when the tcon and dot clock are
indirectly clocked from the PLL-MIPI clock.