ARM: dts: sun8i: fix the pinmux for UART1

When the patch is applied, the allwinner,driver and allwinner,pull
properties are removed.

Although they're described to be optional in the devicetree binding,
without them, the pinmux cannot be initialized, and the uart cannot
be used.

Add them back to fix the problem, and makes the bluetooth on iNet D978
Rev2 board work.

Fixes: 82eec384 (ARM: dts: sun8i: add pinmux for UART1 at PG)
Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>