[iwm] Recognize the IWM_UCODE_TLV_FW_MEM_SEG firmware section type.

* Will be needed for loading version 22 of 7265D firmware.

Obtained from:	DragonflyBSD commit 1d244c8133cf15d00d46836bc48958188cf9f510

sys/dev/iwm/if_iwm.c

@@ -892,6 +892,9 @@ iwm_read_firmware(struct iwm_softc *sc, enum iwm_ucode_type ucode_type)
 			    le32toh(((const uint32_t *)tlv_data)[2]));
 			break;
 
+		case IWM_UCODE_TLV_FW_MEM_SEG:
+			break;
+
 		default:
 			device_printf(sc->sc_dev,
 			    "%s: unknown firmware section %d, abort\n",

sys/dev/iwm/if_iwmreg.h

@@ -1006,6 +1006,7 @@ enum iwm_ucode_tlv_type {
 	IWM_UCODE_TLV_FW_DBG_CONF	= 39,
 	IWM_UCODE_TLV_FW_DBG_TRIGGER	= 40,
 	IWM_UCODE_TLV_FW_GSCAN_CAPA	= 50,
+	IWM_UCODE_TLV_FW_MEM_SEG	= 51,
 };
 
 struct iwm_ucode_tlv {