smsc: Allow 10BASE-T1L/-T1S media

These are Single-Pair Ethernet types (SPE) from 802.3cg. smsc sets the
link flag only if mii_media_active is one of a known set of media types.

Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D60745

sys/dev/usb/net/if_smsc.c

@@ -554,6 +554,8 @@ smsc_miibus_statchg(device_t dev)
 	    (IFM_ACTIVE | IFM_AVALID)) {
 		switch (IFM_SUBTYPE(mii->mii_media_active)) {
 			case IFM_10_T:
+			case IFM_10_T1L:
+			case IFM_10_T1S:
 			case IFM_100_TX:
 				sc->sc_flags |= SMSC_FLAG_LINK;
 				break;