amdgcn: Remove dead defines from gcn-run

amdgcn: Remove dead defines from gcn-run

Nothing uses these since the switch to HSACOv3.

gcc/ChangeLog:

	* config/gcn/gcn-run.c (R_AMDGPU_NONE): Delete.
	(R_AMDGPU_ABS32_LO): Delete.
	(R_AMDGPU_ABS32_HI): Delete.
	(R_AMDGPU_ABS64): Delete.
	(R_AMDGPU_REL32): Delete.
	(R_AMDGPU_REL64): Delete.
	(R_AMDGPU_ABS32): Delete.
	(R_AMDGPU_GOTPCREL): Delete.
	(R_AMDGPU_GOTPCREL32_LO): Delete.
	(R_AMDGPU_GOTPCREL32_HI): Delete.
	(R_AMDGPU_REL32_LO): Delete.
	(R_AMDGPU_REL32_HI): Delete.
	(reserved): Delete.
	(R_AMDGPU_RELATIVE64): Delete.