MIPS: Override assembler target architecture for octeon.

Gas from binutils 2.19 fails to compile some cop1 instructions with
-march=octeon.  Since the cop1 instructions are present in mips1, use
that arch instead.  This will be fixed in binutils 2.20.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mipsregs.h

@@ -1028,6 +1028,8 @@ do {									\
 	__asm__ __volatile__(                                   \
 	".set\tpush\n\t"					\
 	".set\treorder\n\t"					\
+	/* gas fails to assemble cfc1 for some archs (octeon).*/ \
+	".set\tmips1\n\t"					\
         "cfc1\t%0,"STR(source)"\n\t"                            \
 	".set\tpop"						\
         : "=r" (__res));                                        \

arch/mips/kernel/genex.S

@@ -385,10 +385,14 @@ NESTED(nmi_handler, PT_SIZE, sp)
 	.endm
 
 	.macro	__build_clear_fpe
+	.set	push
+	/* gas fails to assemble cfc1 for some archs (octeon).*/ \
+	.set	mips1
 	cfc1	a1, fcr31
 	li	a2, ~(0x3f << 12)
 	and	a2, a1
 	ctc1	a2, fcr31
+	.set	pop
 	TRACE_IRQS_ON
 	STI
 	.endm