[MIPS] Fix optimization for size build.
    
It took a while longer than on other architectures but gcc has finally
started to strike us as well ...
    
This also fixes the damage by 6edfba1b33c701108717f4e036320fc39abe1912.
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
6 files changed