MIPS: Emulate the new MIPS R6 branch compact (BC) instruction

MIPS R6 uses the <R6 LWC2 opcode for the new BC instruction.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c
index cd880b9..1a0a30e 100644
--- a/arch/mips/kernel/branch.c
+++ b/arch/mips/kernel/branch.c
@@ -780,6 +780,15 @@
 			epc += 8;
 		regs->cp0_epc = epc;
 		break;
+#else
+	case bc6_op:
+		/* Only valid for MIPS R6 */
+		if (!cpu_has_mips_r6) {
+			ret = -SIGILL;
+			break;
+		}
+		regs->cp0_epc += 8;
+		break;
 #endif
 	}