Now that the clock driver knows about the available clocks found on the
A20, we can build up the clock tree from the device tree.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The UARTs on the A20 can be muxed to several pins. Add a few options to
the DTSI so that we can start using them in the boards' DT.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The PIO controller is responsible for the GPIO/muxing/external
interrupts handling. Now that we have support for the A20 pin set in the
pinctrl driver, we can start using it in the DTSI.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The Allwinner A20 SoC is based on 2 Cortex A7, an ARM Mali GPU, and is
built to be pin-compatible with the older Allwinner A10.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The Allwinner A31 SoC is a multimedia SoC powered by 4 Cortex-A7 and a
PowerVR GPU.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>