drm/amdkfd: Limit per-process xnack support for GFX12.1

drm/amdkfd: Limit per-process xnack support for GFX12.1

GFX12.1 doesn't support different processes with different xnack
setting. Hence, xnack changes from its default setting needs driver
reload with noretry module parameter.

However, if driver boots-up with xnack on and process sets xnack off,
this condition is supported. In this case, only driver takes xnack off
path whereas hardware / firmware considers xnack is on.

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Reviewed-by: Philip.Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>