drm/amdgpu: Fix PRT flag for gfx12

AMDGPU_PTE_PRT_GFX12 flag is missed during pageTable rework, add it back.

Fixes: 6716a82 ("drm/amdgpu: rework how PTE flags are generated v3")
Signed-off-by: Joe Wang <joe.wang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: JoeWangAMD

drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c

@@ -521,6 +521,7 @@ static void gmc_v12_0_get_vm_pte(struct amdgpu_device *adev,
 		*flags &= ~AMDGPU_PTE_NOALLOC;
 
 	if (vm_flags & AMDGPU_VM_PAGE_PRT) {
+		*flags |= AMDGPU_PTE_PRT_GFX12;
 		*flags |= AMDGPU_PTE_SNOOPED;
 		*flags |= AMDGPU_PTE_SYSTEM;
 		*flags |= AMDGPU_PTE_IS_PTE;