Enable the axp221 PMIC chip in the dts file.

Allows board to power off correctly from the poweroff command

This board requires dc1sw to be enabled in order to provide a power source
for the 5V DCDC converter that powers USB2.

This board uses dldo1 for 3.3V wifi power

This board requires dldo3 to be enabled at 2.8V in order to provide voltage
to the pullup resistors for the i2c0 bus.
Signed-off-by: Lawrence Yu <lyu@micile.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>