Correct baud rate value for UART

bootloaders/zero/sam_ba_serial.c

@@ -108,8 +108,8 @@ void serial_open(void)
     /* Wait for synchronization */
   }
 
-	/* Baud rate 115200 - clock 8MHz -> BAUD value-50436 */
-	uart_basic_init(BOOT_USART_MODULE, 50436, BOOT_USART_PAD_SETTINGS);
+	/* Baud rate 115200 - clock 48MHz -> BAUD value-63018 */
+	uart_basic_init(BOOT_USART_MODULE, 63018, BOOT_USART_PAD_SETTINGS);
 
 	//Initialize flag
 	b_sharp_received = false;