[PATCH, MIPS] Fix disasm of dm[ft]c2 for Octeon

[Nick Clifton]

Hi Adam,

> opcodes/
> 	* mips-opc.c (mips_builtin_opcodes): Move the Octeon-specific
> 	dmfc2 and dmtc2 before the architecture-level variants.
> 
> gas/testsuite/
> 	* gas/mips/octeon.s: Add more tests for dmfc2 and dmtc2.
> 	* gas/mips/octeon.d: Update.
> 	* gas/mips/octeon-ill.l: Update error messages.

Approved - please apply.

Cheers
   Nick