drm/amd/pm: correct pcie spc cap setup

Correct Polaris10 pcie spc cap setting.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c

@@ -2865,6 +2865,8 @@ static int smu7_hwmgr_backend_init(struct pp_hwmgr *hwmgr)
 		data->pcie_gen_cap = adev->pm.pcie_gen_mask;
 		if (data->pcie_gen_cap & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3)
 			data->pcie_spc_cap = 20;
+		else
+			data->pcie_spc_cap = 16;
 		data->pcie_lane_cap = adev->pm.pcie_mlw_mask;
 
 		hwmgr->platform_descriptor.vbiosInterruptId = 0x20000400; /* IRQ_SOURCE1_SW_INT */