randconfig build error with next-20150424, in drivers/gpu/drm/i915

Building with the attached random configuration file,

warning: (SND_SOC_INTEL_BYTCR_RT5640_MACH && SND_SOC_INTEL_CHT_BSW_RT5672_MACH && SND_SOC_INTEL_CHT_BSW_RT5645_MACH) selects SND_SST_IPC_ACPI which has unmet direct dependencies (SOUND && !M68K && !UML && SND && SND_SOC && ACPI)

drivers/built-in.o: In function `intel_backlight_register': (.text+0xfaafa): undefined reference to `backlight_device_register' drivers/built-in.o: In function `intel_backlight_unregister': (.text+0xfab7d): undefined reference to `backlight_device_unregister'