The LCD backlight become consistent on PV1 and DV2

Backlight setting for DV2
feedback resistor is 7.5ohm

Level feedback voltage PMW value
0 19mV 0x1e
1 30mV 0x1d
2 41mV 0x1c
3 53mV 0x1b
4 64.6mV 0x1a
5 88mV 0x18
6 110mV 0x16
7 133mV 0x14
8 154mV 0x12

for PV1
The feedback resistor is 15ohm
0 37.9mV 0x2a
1 61.8mV 0x24
2 78.1mV 0x22
3 103mV 0x1F
4 127mV 0x1C
5 178mV 0x16
6 219mV 0x11
7 267mV 0x0B
8 290mV 0x07