[AMDGPU] Remove dead and broken ComplexPatterns

SelectADDRParam was discovered as being dead 5 years ago and removed in
7b4ef068 but the unused ComplexPattern definition was left behind.
SelectADDRDWord has never existed as far as I can tell, even back when
AMDGPU was R600-only and called that.

Reviewed By: foad

Differential Revision: https://reviews.llvm.org/D108758