drm/amdkfd: hard-code cacheline for gc943,gc944

Cacheline size is not available in IP discovery for gc943,gc944.

Signed-off-by: David Yat Sin <David.YatSin@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org