arm64: dts: hisilicon: list all clocks required by snps-dw-apb-uart.yaml

The snps,dw-apb-uart binding need to specify two clocks: "baudclk",
"apb_pclk". But only "apb_pclk" is specified now. Because the driver
preferentially matches the first clock. Otherwise, it matches the second
clock instead of both clocks. So both of them use the same clock don't
change the function.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>