ARM: dts: sun8i: Move A23/A33 usbphy and usb_otg nodes to common dtsi

The usbphy and usb_otg nodes in the A23 and A33 dts files only differ
by compatible, and for the usbphy, the size of one of its register
regions.

Move all the common bits to the A23/A33 common dtsi file.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>