serial: zynq: Remove duplicated header

debug_uart.h is included twice.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>

drivers/serial/serial_zynq.c

@@ -192,9 +192,6 @@ U_BOOT_DRIVER(serial_zynq) = {
 };
 
 #ifdef CONFIG_DEBUG_UART_ZYNQ
-
-#include <debug_uart.h>
-
 void _debug_uart_init(void)
 {
 	struct uart_zynq *regs = (struct uart_zynq *)CONFIG_DEBUG_UART_BASE;