arm64: allwinner: axp81x: Fix double invertion for FLDO1

This fix booting on A64 boards when disabling the unused regulators at boot.
We did disable all the regulator handled by register 0x13 which of course contain
mandatory regulators for the board to be up.

Reported by: Mark Millard <marklmi@yahoo.com>
X-MFC-With: r340848