ARM64: DTS: Add rk3399-firefly uart4 device, node as /dev/ttyS1
drwxr-xr-x - amso1100
drwxr-xr-x - cxgb3
drwxr-xr-x - ehca
drwxr-xr-x - ipath
drwxr-xr-x - mthca