MIPS: add .module arch and ase to all output asm

MIPS: add .module arch and ase to all output asm

Currently, the asm output file for MIPS has no rev info.
It can make some trouble, for example:

  assembler is mips1 by default,
  gcc is fpxx by default.

To assemble the output of gcc -S, we have to pass -mips2
to assembler.

The same situation is for some CPU has extension insn.
Octeon is an example.
So we can just add ".set arch=octeon".

If an ASE is enabled, .module ase will also be used.

gcc/ChangeLog:
	* config/mips/mips.c (mips_file_start): add .module for
	  arch and ase.