arm64: dts: rockchip: Fix name for UART pin header on qnap-ts433

I typoed the pin header name when copying it from my notes on paper.

Fixes: 9da1c032

 ("arm64: dts: rockchip: Add basic support for QNAP TS-433")
Signed-off-by: Uwe Kleine-König <ukleinek@debian.org>
Link: https://lore.kernel.org/r/20240301163201.559787-2-ukleinek@debian.org


Signed-off-by: Heiko Stuebner <heiko@sntech.de>