MIPS: Don't clobber CP0_STATUS value for CONFIG_MIPS_MT_SMTC

Reported-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Patchwork: https://patchwork.linux-mips.org/patch/2753/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/stackframe.h

@@ -195,9 +195,9 @@
 		 * to cover the pipeline delay.
 		 */
 		.set	mips32
-		mfc0	v1, CP0_TCSTATUS
+		mfc0	k0, CP0_TCSTATUS
 		.set	mips0
-		LONG_S	v1, PT_TCSTATUS(sp)
+		LONG_S	k0, PT_TCSTATUS(sp)
 #endif /* CONFIG_MIPS_MT_SMTC */
 		LONG_S	$4, PT_R4(sp)
 		LONG_S	$5, PT_R5(sp)