console: USB: KBD: Fix incorrect autoboot timeout

Autoboot timeout defined by CONFIG_BOOTDELAY will not be accurate if
CONFIG_USB_KEYBOARD and CONFIG_SYS_USB_EVENT_POLL are defined in
configuration file and when tstc() function for checking key pressed
takes longer time than 10 ms (e.g., 50 ms) to finish.

Signed-off-by: Jim Lin <jilin@nvidia.com>
diff --git a/common/main.c b/common/main.c
index 5d8454e..9e92687 100644
--- a/common/main.c
+++ b/common/main.c
@@ -225,6 +225,7 @@
 int abortboot(int bootdelay)
 {
 	int abort = 0;
+	unsigned long ts;
 
 #ifdef CONFIG_MENUPROMPT
 	printf(CONFIG_MENUPROMPT);
@@ -248,11 +249,10 @@
 #endif
 
 	while ((bootdelay > 0) && (!abort)) {
-		int i;
-
 		--bootdelay;
-		/* delay 100 * 10ms */
-		for (i=0; !abort && i<100; ++i) {
+		/* delay 1000 ms */
+		ts = get_timer(0);
+		do {
 			if (tstc()) {	/* we got a key press	*/
 				abort  = 1;	/* don't auto boot	*/
 				bootdelay = 0;	/* no more delay	*/
@@ -264,7 +264,7 @@
 				break;
 			}
 			udelay(10000);
-		}
+		} while (!abort && get_timer(ts) < 1000);
 
 		printf("\b\b\b%2d ", bootdelay);
 	}