mips-dec-bsd and mips-pe

[Alan Modra]

Both of these targets fail with
tc-mips.o(.rodata+0x2a4): In function `md_begin':
.../gas/config/tc-mips.c:1258: undefined reference to `ecoff_directive_extern'

They also failed with 2.13.  The lack of bug reports (besides mine)
says to me that there are zero users for these targets.  Let's remove
the configury bits before 2.14 goes out the door.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre