add sfc_tmp node for temperature sensor
Based on sfc_tmp from starfive_vic7100_evb.dts in @tekkamanninja branch Fedora_VIC_7100_2021.04
```
# dmesg |grep sfc_temp
[ 3.770961] sfc_temp_sensor 124a0000.tmpsensor: probe
# cat /sys/bus/platform/drivers/sfc_temp_sensor/124a0000.tmpsensor/temp1_input
40.84
```