drm/amdgpu: change pcie_gen_cap magic code to macro

This patch changes pcie_gen_cap magic code to macro to make it more
readable.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Cc: Eric Huang <JinHuiEric.Huang@amd.com>
Cc: Ken Wang <Qingqing.Wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/fiji_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/fiji_hwmgr.c
index 6831fae..744aa88 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/fiji_hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/fiji_hwmgr.c
@@ -733,7 +733,7 @@
 		sys_info.info_id = CGS_SYSTEM_INFO_PCIE_GEN_INFO;
 		result = cgs_query_system_info(hwmgr->device, &sys_info);
 		if (result)
-			data->pcie_gen_cap = 0x30007;
+			data->pcie_gen_cap = AMDGPU_DEFAULT_PCIE_GEN_MASK;
 		else
 			data->pcie_gen_cap = (uint32_t)sys_info.value;
 		if (data->pcie_gen_cap & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3)
@@ -742,7 +742,7 @@
 		sys_info.info_id = CGS_SYSTEM_INFO_PCIE_MLW;
 		result = cgs_query_system_info(hwmgr->device, &sys_info);
 		if (result)
-			data->pcie_lane_cap = 0x2f0000;
+			data->pcie_lane_cap = AMDGPU_DEFAULT_PCIE_MLW_MASK;
 		else
 			data->pcie_lane_cap = (uint32_t)sys_info.value;
 	} else {