drm/amdgpu: Reserve 0-2 invalidation reg sets for none-amdgpu usages

Firmware used reg set 2 for tlb invalidation. AMDGPU can start from reg
set 3 to avoid the conflict. AMDKFD will use the reg set 0 or 1 when
necesary.
Signed-off-by: Shaoyun Liu <Shaoyun.Liu@amd.com>
Reviewws-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -386,7 +386,7 @@ static int gmc_v9_0_early_init(void *handle)
 static int gmc_v9_0_late_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
-	unsigned vm_inv_eng[AMDGPU_MAX_VMHUBS] = { 0 };
+	unsigned vm_inv_eng[AMDGPU_MAX_VMHUBS] = { 3, 3 };
 	unsigned i;
 
 	for(i = 0; i < adev->num_rings; ++i) {