ARM: zynq: Fix incorrect reference to XM013 instead of XM011

Fix comment about targeted extension card. It was likely just c&p error.

Signed-off-by: Michal Simek <[e-mail]>
Link: https://lore.kernel.org/r/39e1[e-mail]

arch/arm/boot/dts/zynq-zc770-xm011.dts

···
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Xilinx ZC770 XM013 board DTS
+ * Xilinx ZC770 XM011 board DTS
  *
  * Copyright (C) 2013-2018 Xilinx, Inc.
  */