sc7180: report hardware watchdog reset after reboot

add WATCHDOG_TOMBSTONE in memlayout.ld

Change-Id: I57ece39ff3d49f2bab259cbd92ab039a49323119
Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44868
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
diff --git a/src/soc/qualcomm/sc7180/memlayout.ld b/src/soc/qualcomm/sc7180/memlayout.ld
index 94300e8..0142242 100644
--- a/src/soc/qualcomm/sc7180/memlayout.ld
+++ b/src/soc/qualcomm/sc7180/memlayout.ld
@@ -27,7 +27,8 @@
 	SSRAM_END(0x146AE000)
 
 	BSRAM_START(0x14800000)
-	REGION(pbl_timestamps, 0x14800000, 84K, 4K)
+	REGION(pbl_timestamps, 0x14800000, 83K, 4K)
+	WATCHDOG_TOMBSTONE(0x14814FFC, 4)
 	BOOTBLOCK(0x14815000, 40K)
 	PRERAM_CBFS_CACHE(0x1481F000, 70K)
 	PRERAM_CBMEM_CONSOLE(0x14830800, 32K)