MIPS: Loongson 2 needs no hazard barriers.

Quoting from Loongson2FUserGuide.pdf:

5.22.1 Hazards
The processor detects most of the pipeline hazards in hardware, including
CP0 hazards and load hazards. No NOP instructions are required to correct
instruction sequences.

Signed-off-by: Zhang Le <r0bertz@gentoo.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>