or1k: Fix messages for relocations in shared libraries

or1k: Fix messages for relocations in shared libraries

Added checks include:

 - Do not allow relocations to global symbols using relocations which are
   meant for local symbol relocations.
 - Require the use of -fpic when compiling shared libraries.
 - Require zero addend for plt relocations.

bfd/ChangeLog:

yyyy-mm-dd  Richard Henderson  <rth@twiddle.net>

	* elf32-or1k.c (or1k_elf_relocate_section): Add error for unknown
	relocations.  Add error for non zero addend with plt and got
	relocations.  Add error for got and plt references against dynamic, non
	local, symbols.  Add error when linking non shared liraries with
	flag_pic.