riscv: Clear type 6 triggers on connecting.

I missed this when I first add mcontrol6 support.

https://github.com/riscv/riscv-openocd/pull/648

Change-Id: I1a2706c7ea3a6757ed5083091cd2c764a8b0267c
Signed-off-by: Tim Newsome <tim@sifive.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6684
Tested-by: jenkins
Reviewed-by: Jan Matyas <matyas@codasip.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/target/riscv/riscv.c

@@ -3569,6 +3569,10 @@ int riscv_enumerate_triggers(struct target *target)
 				if (tdata1 & MCONTROL_DMODE(riscv_xlen(target)))
 					riscv_set_register(target, GDB_REGNO_TDATA1, 0);
 				break;
+			case 6:
+				if (tdata1 & MCONTROL_DMODE(riscv_xlen(target)))
+					riscv_set_register(target, GDB_REGNO_TDATA1, 0);
+				break;
 		}
 	}