remove -DTiklock, a vestage of a former era

Reference: /n/atom/patch/applied/k10mkclean
Date: Mon Aug 17 05:54:05 CES 2015
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/mkfile	Mon Aug 17 05:53:56 2015
+++ /sys/src/nix/k10/mkfile	Mon Aug 17 05:53:57 2015
@@ -7,7 +7,7 @@
 
 nix:V:	$p$CONF
 
-CFLAGS=-FVTw -DTiklock
+CFLAGS=-FVTW
 <| awk -f ../mk/parse $CONF
 <../mk/bootmkfile
 <../mk/portmkfile