i2c: deblock i2c bus also if accessed before realocation

If we switch to a different i2c bus in changing the mux config for the
i2c mux, we have to be sure to deblock the bus also before realocation.
Signed-off-by: NHolger Brunck <holger.brunck@keymile.com>
cc: Heiko Schocher <hs@denx.de>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>

common/cmd_i2c.c

@@ -1445,6 +1445,7 @@ int i2c_mux_ident_muxstring_f (uchar *buf)
 		oldpos = pos;
 
 	}
+	i2c_init_board();
 
 	return 0;
 }