other/7254: GCC Error target = MN10200

[Steven Bosscher]

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7254

This target has been declared obsolete (ref. 
gcc.gnu.org/gcc-3.3/changes.html):

    * Matsushita MN10200, |mn10200-*-*|

The PR hasn't been touched for over half a year now and should be in 
feedback state.

Greetz
Steven