sunxi: board: Fix UART PortF pinmux setup

When CONFIG_UART0_PORT_F is defined, we try to configure two PortF pins
(usually used for the SD card) as UART0. Some SoCs use the mux value of
3 for this, while others use 4.

The combination of Kconfig symbols we currently use was not quite right:
we mis-configure the A31, A64, H6 and H616.

Going through the list in the pinctrl driver, there are only a few older
SoCs that use a value of 4, so revert the #ifdef clause, and name those
explicitly, instead of the other way around.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>