Remove unused Zedboard config files. files.zedboard was empty other than

comments, and std.zedboard just pointed to files.zedboard and std.xilinx.

sys/arm/conf/ZEDBOARD

@@ -22,7 +22,7 @@
 ident		ZEDBOARD
 
 include 	"std.armv6"
-include 	"../xilinx/zedboard/std.zedboard"
+include 	"../xilinx/std.zynq7"
 
 options 	SCHED_ULE		# ULE scheduler
 #options 	NFSSD			# Network Filesystem Server

sys/arm/xilinx/zedboard/files.zedboard

@@ -1,9 +0,0 @@
-#
-# files.zedboard
-#
-# $FreeBSD$
-
-#   We'll need board specific files once we start implementing drivers
-#   for Zedboard PL peripherals such as HDMI, VGA, or Audio Codecs.  For
-#   now, nothing is needed.
-#

sys/arm/xilinx/zedboard/std.zedboard

@@ -1,8 +0,0 @@
-#
-# std.zedboard
-#
-# $FreeBSD$
-
-include "../xilinx/std.zynq7"
-files	"../xilinx/zedboard/files.zedboard"
-