arm64: dts: rockchip: corrected uart1 clock-names for rk3328

Corrected the uart clock-names or the uart driver might fail.

Fixes: 52e02d37 ("arm64: dts: rockchip: add core dtsi file for RK3328 SoCs")
Cc: stable@vger.kernel.org
Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>