at32f43x: Log contents of DEBUG Series ID register in case UID is unr…

…eadable

src/target/at32f43x.c

@@ -376,8 +376,10 @@ bool at32f43x_probe(target_s *target)
 	const uint16_t part_id = idcode & AT32F4x_IDCODE_PART_MASK;
 	// ... and highest byte of UID
 	const uint8_t project_id = target_mem32_read8(target, AT32F4x_PROJECT_ID);
+	const uint32_t debug_ser_id = target_mem32_read32(target, AT32F43x_DBGMCU_SER_ID);
 
-	DEBUG_TARGET("%s: idcode = %08" PRIx32 ", project_id = %02x\n", __func__, idcode, project_id);
+	DEBUG_TARGET("%s: idcode = %08" PRIx32 ", project_id = %02x, debug_ser_id = %08" PRIx32 "\n", __func__, idcode,
+		project_id, debug_ser_id);
 
 	/* 0x0e: F437 (has EMAC), 0x0d: F435 (no EMAC). 4K/2K describe sector sizes, not total flash capacity. */
 	if ((series == AT32F43_SERIES_4K || series == AT32F43_SERIES_2K) && (project_id == 0x0dU || project_id == 0x0eU))