Add cat back to the ramfs

It's really impossible to debug networking without cat.

Change-Id: I08b3519093edfa10baaa247feb26203fb9e726ae
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>

sys/src/9/k10/k8cpu

@@ -125,7 +125,7 @@ rootdir
 	/amd64/bin/bind
 	/amd64/bin/mount
 	/amd64/bin/echo
-#	/amd64/bin/cat
+	/amd64/bin/cat
 	/amd64/bin/ls
 #	/amd64/bin/cp
 #	/amd64/bin/ps

sys/src/9/k10/k8cpu.json

@@ -31,7 +31,10 @@
 	"data2c _amd64_bin_date date.elf.out>> k8cpu.root.c",
 	"cp $HARVEY/amd64/bin/ls ls.elf.out",
 	"strip ls.elf.out",
-	"data2c _amd64_bin_ls ls.elf.out>> k8cpu.root.c"
+	"data2c _amd64_bin_ls ls.elf.out>> k8cpu.root.c",
+	"cp $HARVEY/amd64/bin/cat cat.elf.out",
+	"strip cat.elf.out",
+	"data2c _amd64_bin_cat cat.elf.out>> k8cpu.root.c"
     ],
     "SourceFiles":[
 	"cga.c",