serial: imx: fix comment about which machines use the i.MX21 type

Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

@@ -182,7 +182,7 @@
 
 #define UART_NR 8
 
-/* i.mx21 type uart runs on all i.mx except i.mx1 */
+/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
 enum imx_uart_type {
 	IMX1_UART,
 	IMX21_UART,