ns16550: kick watchdog while waiting for a character

ns16550 busyloops waiting for incoming byte causing watchdog to reboot
while waiting for a key press. A call to WATCHDOG_RESET in NS16550_getc
loop fixes it.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>

drivers/serial/ns16550.c

@@ -6,6 +6,7 @@
 
 #include <config.h>
 #include <ns16550.h>
+#include <watchdog.h>
 
 #define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
 #define UART_MCRVAL (UART_MCR_DTR | \
@@ -70,6 +71,7 @@ char NS16550_getc (NS16550_t com_port)
 		extern void usbtty_poll(void);
 		usbtty_poll();
 #endif
+		WATCHDOG_RESET();
 	}
 	return (com_port->rbr);
 }