Building with the attached random configuration file,

drivers/built-in.o: In function `panel_simple_probe': panel-simple.c:(.text+0x37cfd): undefined reference to `of_find_backlight_by_node' drivers/built-in.o: In function `sharp_panel_probe': panel-sharp-lq101r1sx01.c:(.text+0x383ef): undefined reference to `of_find_backlight_by_node' make: *** [vmlinux] Error 1