pch_uart: add missing comment about OKI ML7223

Signed-off-by: NAlexander Stein <alexander.stein@systec-electronic.com>
Reviewed-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/pch_uart.c

@@ -45,6 +45,7 @@ enum {
 /* Set the max number of UART port
  * Intel EG20T PCH: 4 port
  * OKI SEMICONDUCTOR ML7213 IOH: 3 port
+ * OKI SEMICONDUCTOR ML7223 IOH: 2 port
 */
 #define PCH_UART_NR	4