[Kernel][Hardware][AMD] Bf16 mfma opt for ROCm skinny GEMMs (vllm-project#17071)

Signed-off-by: Hashem Hashemi <hashem.hashemi@amd.com>
Signed-off-by: charlifu <charlifu@amd.com>
Co-authored-by: charlifu <charlifu@amd.com>
Signed-off-by: Yuqi Zhang <yuqizhang@google.com>

Author: 2 people