MIPS: mm: Fix duplicate "const" on insn_table_MM

Fix the following gcc 7.x build error on microMIPS builds:

arch/mips/mm/uasm-micromips.c:43:26: error: duplicate ‘const’ declaration specifier [-Werror=duplicate-decl-specifier]
 static const struct insn const insn_table_MM[insn_invalid] = {
                          ^~~~~

The same issue has already been fixed in uasm-mips by commit
00e06297b3 ("MIPS: mm: remove duplicate "const" qualifier on
insn_table").

Signed-off-by: James Hogan <jhogan@kernel.org>
Fixes: ce807d5f67 ("MIPS: Optimize uasm insn lookup.")
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17889/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/uasm-micromips.c

@@ -40,7 +40,7 @@
 
 #include "uasm.c"
 
-static const struct insn const insn_table_MM[insn_invalid] = {
+static const struct insn insn_table_MM[insn_invalid] = {
 	[insn_addu]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_addu32_op), RT | RS | RD},
 	[insn_addiu]	= {M(mm_addiu32_op, 0, 0, 0, 0, 0), RT | RS | SIMM},
 	[insn_and]	= {M(mm_pool32a_op, 0, 0, 0, 0, mm_and_op), RT | RS | RD},