mb/system76/rpl: lemp12: Add timeouts for PCIE RPs

The FSP may fail to detect PCIe 4.0 devices in PCIe 3.0 slots on S3
resume.

Change-Id: Ib2efec2febc9f6c25b1dd8766fa08c560365325d
Signed-off-by: Tim Crawford <tcrawford@system76.com>

src/mainboard/system76/rpl/variants/lemp12/overridetree.cb

@@ -77,6 +77,7 @@ chip soc/intel/alderlake
 				.clk_src = 1,
 				.clk_req = 1,
 				.flags = PCIE_RP_LTR,
+				.pcie_rp_detect_timeout_ms = 50,
 			}"
 		end
 	end