drm/amdkfd: Fix -Wunused-const-variable warning

If KFD_SUPPORT_IOMMU_V2 is not set, gcc warns:

drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device.c:121:37: warning: ‘raven_device_info’ defined but not used [-Wunused-const-variable=]
 static const struct kfd_device_info raven_device_info = {
                                     ^~~~~~~~~~~~~~~~~

As Huang Rui suggested, Raven already has the fallback path,
so it should be out of IOMMU v2 flag.
Suggested-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_device.c

@@ -503,8 +503,8 @@ static const struct kfd_device_info *kfd_supported_devices[][2] = {
 #ifdef KFD_SUPPORT_IOMMU_V2
 	[CHIP_KAVERI] = {&kaveri_device_info, NULL},
 	[CHIP_CARRIZO] = {&carrizo_device_info, NULL},
-	[CHIP_RAVEN] = {&raven_device_info, NULL},
 #endif
+	[CHIP_RAVEN] = {&raven_device_info, NULL},
 	[CHIP_HAWAII] = {&hawaii_device_info, NULL},
 	[CHIP_TONGA] = {&tonga_device_info, NULL},
 	[CHIP_FIJI] = {&fiji_device_info, &fiji_vf_device_info},