Deprecate a number of less used 10 and 10/100 Ethernet devices.

Deprecate a number of less used 10 and 10/100 Ethernet devices.

The current deprecated list is: ae, bm, cs, de, dme, ed, ep, ex, fe,
pcn, sf, sn, tl, tx, txp, vx, wb, xe

The list as refined as part of FCP-0101. Per the FCP, devices may be
removed from the deprecation list if enough users are found or they are
converted to iflib.

FCP:	https://github.com/freebsd/fcp/blob/master/fcp-0101.md