arm64: dts: lg: Add missing PL011 "uartclk"

arm64: dts: lg: Add missing PL011 "uartclk"

The PL011 IP has 2 clock inputs for UART core/baud and APB bus. The
LG131x SoCs are missing the core "uartclk". In this case, the Linux
driver uses single clock for both clock inputs. Let's assume that's how
the h/w is wired and make the DT reflect that.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Chanho Min <chanho.min@lge.com>
Link: https://lore.kernel.org/r/20250609-dt-lg-fixes-v1-2-e210e797c2d7@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>