riscv: k210: Enable QSPI for spi3

This device has four IOs connected to the SPI flash. Add the appropriate
bindings.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Leo Liang <ycliang@andestech.com>
1 file changed