zynq: Add zynq_zc770 xm013 board support

ZC770 is a complete development board based on the Xilinx Zynq-7000
All Programmable SoC, similar to ZC70x board but which has four
different daughter cards, like XM010, XM011, XM012 and XM013

ZC770 XM013:
- 1GB DDR3
- 128 Mb Quad-SPI Flash(dual parallel)
- USB-UART

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
diff --git a/boards.cfg b/boards.cfg
index 02e144f..19905d0 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -361,6 +361,7 @@
 Active  arm	    armv7	   zynq	       xilinx	       zynq	   	   zynq_zed				-                                                                                                                                 Michal Simek <monstr@monstr.eu>:Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
 Active  arm	    armv7	   zynq	       xilinx	       zynq	   	   zynq_microzed			-                                                                                                                                 Michal Simek <monstr@monstr.eu>:Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
 Active  arm	    armv7	   zynq	       xilinx	       zynq	   	   zynq_zc770_xm010			zynq_zc770:ZC770_XM010                                                                                                            Michal Simek <monstr@monstr.eu>:Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
+Active  arm	    armv7	   zynq	       xilinx	       zynq	   	   zynq_zc770_xm013			zynq_zc770:ZC770_XM013                                                                                                            Michal Simek <monstr@monstr.eu>:Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
 Active  arm         armv7:arm720t  tegra114    nvidia          dalmore             dalmore                              -                                                                                                                                 Tom Warren <twarren@nvidia.com>
 Active  arm         armv7:arm720t  tegra20     avionic-design  medcom-wide         medcom-wide                          -                                                                                                                                 Alban Bedel <alban.bedel@avionic-design.de>
 Active  arm         armv7:arm720t  tegra20     avionic-design  plutux              plutux                               -                                                                                                                                 Alban Bedel <alban.bedel@avionic-design.de>