[AMDGPU][True16][MC] add true16/fake16 flag to gfx12 dasm tests (llvm#106469)

add true16/fake16 flag to gfx12 dasm tests including vop1, vop1_dpp,
vop3_from_vop1 and vop3_from_vop1_dpp. This is a test only change.

Author: broxigarchen