ARM64: zynqmp: Remove incorrect link to common config file

Link to zynqmp common file is incorrect. Fix it by removing the whole
link because it is visible from the file where to look at it.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

include/configs/xilinx_zynqmp_ep.h

@@ -1,7 +1,5 @@
 /*
- * Configuration for Xilinx ZynqMP emulation
- * platforms. See zynqmp-common.h for ZynqMP
- * common configs
+ * Configuration for Xilinx ZynqMP emulation platforms
  *
  * (C) Copyright 2014 - 2015 Xilinx, Inc.
  * Michal Simek <michal.simek@xilinx.com>