drivers/net: delete 486 Apricot support

The Apricot was a 486 PC with 4MB RAM, and an on-board ethernet
via an intel i82596 hard-wired to i/o 0x300.

Those who were using linux in the 1990's will recall that the
i82596 driver was not one of the more stable or widely used
drivers of its day.  Combine that with the extremely limited
resources of the platform, and it is truly time to expire the
support for this thing.

There are some old m68k targets who were also using this chip,
so rather than poll the m68k user base, we simply cut out the
x86/Apricot support here in this commit.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>