Remove never used BSM{,_MASK}. BSM_MASK #define also causes a warning.
include/drm/i915_drm.h:96:34: warning: result of β65535 << 20β
requires 37 bits to represent, but βintβ only has 32 bits
[-Wshiftoverflow=]
#define INTEL_BSM_MASK (0xFFFF << 20)