mb/google/poppy: enable AER for PCIe root port 0

Enable PCIe Advanced Error Reporting for PCIe root port 0.

BUG=b:64798078
TEST="lspci" shows that AER is enabled in the capabilities list.

Change-Id: I8a818a9539b8d4f103d551ffd59713c9bbbc13ce
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/21425
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/mainboard/google/poppy/variants/baseboard/devicetree.cb b/src/mainboard/google/poppy/variants/baseboard/devicetree.cb
index 5b81fc0..0bd2efc 100644
--- a/src/mainboard/google/poppy/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/poppy/variants/baseboard/devicetree.cb
@@ -152,6 +152,8 @@
 	register "PcieRpClkReqSupport[0]" = "1"
 	# RP 1 uses SRCCLKREQ1#
 	register "PcieRpClkReqNumber[0]" = "1"
+	# RP 1, Enable Advanced Error Reporting
+	register PcieRpAdvancedErrorReporting[0] = "1"
 
 	register "usb2_ports[0]" = "USB2_PORT_LONG(OC0)"	# Type-C Port 1
 	register "usb2_ports[1]" = "USB2_PORT_MID(OC_SKIP)"	# Type-A Port