sunxi: power: Columbus: only enable ELDO3 when necessary

ELDO3 is only necessary when using the lcd-panel, and not when using hdmi,
the display code already takes care of enabling ELDO3 when necessary,
so there is no need to permanently enable it in the deconfig.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>