mb/supermicro/x11-lga1151-series: fix PNP warning for SUART1/2

Fix PNP warning about missing devicetree entry for SUART1/2 by setting
register 0xF0 to a sane (default) value.

Change-Id: Ie852696aae09b9b03cebd6c3d8cbbd53a7138d89
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39094
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/mainboard/supermicro/x11-lga1151-series/variants/x11ssh-tf/overridetree.cb b/src/mainboard/supermicro/x11-lga1151-series/variants/x11ssh-tf/overridetree.cb
index f481c77..074e61b 100644
--- a/src/mainboard/supermicro/x11-lga1151-series/variants/x11ssh-tf/overridetree.cb
+++ b/src/mainboard/supermicro/x11-lga1151-series/variants/x11ssh-tf/overridetree.cb
@@ -100,10 +100,12 @@
 						device pnp 2e.2 on	# SUART1
 							io 0x60 = 0x3f8
 							irq 0x70 = 4
+							drq 0xf0 = 0x00
 						end
 						device pnp 2e.3 on	# SUART2
 							io 0x60 = 0x2f8
 							irq 0x70 = 3
+							drq 0xf0 = 0x00
 						end
 						device pnp 2e.4 on	# SWC
 							io 0x60 = 0xa00