or1k: Add mrori option, fix option docs

or1k: Add mrori option, fix option docs

gcc/ChangeLog:

	* config.gcc (or1k*-*-*): Add mrori and mror to validation.
	* doc/invoke.texi (OpenRISC Options): Add mrori option, rewrite all
	documenation to be more clear.
	* config/or1k/elf.opt (mboard=, mnewlib): Rewrite documentation to be
	more clear.
	* config/or1k/or1k.opt (mrori): New option.
	(mhard-div, msoft-div, mhard-mul, msoft-mul, mcmov, mror, msext,
	msfimm, mshftimm): Rewrite documentation to be more clear.
	* config/or1k/or1k.md (insn_support): Add ror and rori.
	(enabled): Add conditions for ror and rori.
	(rotrsi3): Replace condition for shftimm with ror and rori.

gcc/testsuite/ChangeLog:

	* gcc.target/or1k/ror-4.c: New file.
	* gcc.target/or1k/shftimm-1.c: Update test from rotate to shift
	as the shftimm option no longer controls rotate.

From-SVN: r273649