MIPS: Remove execution hazard barriers for Octeon.

The Octeon has no execution hazards, so we can remove them and save an
instruction per TLB handler invocation.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Reviewed by: David VomLehn <dvomlehn@cisco.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h

@@ -47,6 +47,7 @@
 #define cpu_has_mips32r2	0
 #define cpu_has_mips64r1	0
 #define cpu_has_mips64r2	1
+#define cpu_has_mips_r2_exec_hazard 0
 #define cpu_has_dsp		0
 #define cpu_has_mipsmt		0
 #define cpu_has_userlocal	0