obsolete configurations

[Francesco Potorti`]

The recent latest gdb release obsoleted the following configurations.
Maybe they could also be removed from Emacs?

================
* OBSOLETE configurations and files

Configurations that have been declared obsolete in this release have
been commented out.  Unless there is activity to revive these
configurations, the next release of GDB will have their sources
permanently REMOVED.

Mitsubishi D30V                                 d30v-*-*
OS/9000                                         i[34]86-*-os9k
IBM AIX PS/2                                    i[3456]86-*-aix
Fujitsu FR30                                    fr30-*-elf*
Motorola Delta 88000 running Sys V              m88k-motorola-sysv  or  delta88
Argonaut Risc Chip (ARC)                        arc-*-*
i386 running Mach 3.0                           i[3456]86-*-mach3*
i386 running Mach                               i[3456]86-*-mach*
i386 running OSF/1                              i[3456]86-*osf1mk*
HP/Apollo 68k Family                            m68*-apollo*-sysv*,
                                                m68*-apollo*-bsd*,
                                                m68*-hp-bsd*, m68*-hp-hpux*
I960 with MON960                                i960-*-coff