[binutils-gdb] Reinstate mips ecoff support

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 8e415ce8fee234cd86f29d8f4ebbbdf0f9c0b031 ***

Author: Alan Modra <amodra@gmail.com>
Branch: master
Commit: 8e415ce8fee234cd86f29d8f4ebbbdf0f9c0b031

Reinstate mips ecoff support

	* Makefile.am: Revert 2018-04-18 coff-mips changes.
	* config.bfd: Add back mips_ecoff_le_vec and mips_ecoff_be_vec
	to selvecs for mips targets change 2018-04-18.
	* configure.ac: Reinstate mips_ecoff_le_vec, mips_ecoff_be_vec
	and  mips_ecoff_bele_vec.
	* targets.c: Likewise.
	* coff-mips.c: Resurrect.
	* Makefile.in: Regenerate.
	* configure: Regenerate.
	* po/SRC-POTFILES.in: Regenerate.