[AMDGPU] Add 224-bit vector types and link 192-bit types to MVTs

Add SReg_224, VReg_224, AReg_224, etc.
Link 224-bit types with v7i32/v7f32.
Link existing 192-bit types to newly added v3i64/v3f64/v6i32/v6f32.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D104622