This patch adds UART1~3 support for K210, and separates the rt_uart_ops of
UARTHS from UART.
This patch add configs in Kconfig for configuring the pins of UARTx,
please check the sysctl_set_power_mode for the pins in the io_config_init
of bsp/k210/driver/drv_io_config.c
Signed-off-by: NFu Wei <wefu@redhat.com>