ARM: dts: sunxi: Add regulator-boot-on to usb host port regulator nodes

u-boot will have turned on the power to the usb host ports, so mark them
as regulator-boot-on, this stops the power on the ports from temporarily
getting turned off during boot, causing issues with e.g. usb powered
harddisks.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>