drm/amdgpu: switch to ih_init_register_offset for navi10

Initialize ih control registers offset through helper
function navi10_ih_init_register_offset.
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Dennis Li <Dennis.Li@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/navi10_ih.c

@@ -847,6 +847,9 @@ static int navi10_ih_sw_init(void *handle)
 					(adev->doorbell_index.ih + 2) << 1;
 	}
 
+	/* initialize ih control registers offset */
+	navi10_ih_init_register_offset(adev);
+
 	r = amdgpu_ih_ring_init(adev, &adev->irq.ih_soft, PAGE_SIZE, true);
 	if (r)
 		return r;