Make room for media types of the future. Extend the ifmedia word to 64 bits.
This changes numbers of the SIOCSIFMEDIA and SIOCGIFMEDIA ioctls and
grows struct ifmediareq.

Old ifconfig and dhclient binaries can still assign addresses, however
the 'media' subcommand stops working. Recompiling ifconfig and dhclient
with new headers before a reboot should not be necessary unless in very
special circumstances where non-default media settings must be used to
get link and console access is not available.

There may be some MD fallout but that will be cleared up later.

ok deraadt miod
with help and suggestions from several sharks attending l2k15

Convert to if_input(), ok miod@

Sync the MI LANCE code ( le(4) ) with NetBSD, except for the following:
- the am7990_get() - now lance_get() - is unchanged.
- the interrupt acknowledge logic is unchanged, and will disable interrupts,
then acknowledge all interrupt conditions.

Add ILACC (79900) support (from NetBSD).

Both LANCE (am7990.c) and ILACC (am79900.c) code share as much common code
(lance.c) as possible. This affects all le(4) attachments, but the changes
are mostly mechanical, to split am7990-specific parts from lance-agnostic
parts.

Compile tested on all affected platforms. Tested on alpha, hp300, luna88k,
mvme88k, sparc, sparc64 and vax.