arm64: dts: rockchip: Fix UART pull-ups on rk3328

arm64: dts: rockchip: Fix UART pull-ups on rk3328

For UARTs, the local pull-ups should be on the RX pin, not the TX pin.
UARTs transmit active-low, so a disconnected RX pin should be pulled
high instead of left floating to prevent noise being interpreted as
transmissions.

This gets rid of bogus sysrq events when the UART console is not
connected.

Fixes: 52e02d377a72 ("arm64: dts: rockchip: add core dtsi file for RK3328 SoCs")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20201204064805.6480-1-wens@kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>