arm64: allwinner: h5: add support for Orange Pi Prime board

Orange Pi Prime is a new Allwinner H5-based SBC by Xunlong.

It's like a Orange Pi Plus 2E with H3 replaced with H5, eMMC replaced
with onboard SPI NOR Flash and wireless card changed to Realtek
RTL8723BS (with Bluetooth functionality).

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>