9 kernels: remove reboot.h on mk clean

Reference: /n/atom/patch/applied2013/9rmreboot.h
Date: Sat Sep 21 20:34:18 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/9/port/portmkfile	Sat Sep 21 20:34:14 2013
+++ /sys/src/9/port/portmkfile	Sat Sep 21 20:34:14 2013
@@ -33,7 +33,7 @@
 ALLLIST=`{echo $CONFLIST $CRAPLIST}
 
 clean:V: ${ALLLIST:%=%.clean}
-	rm -f *.[$OS] *.root.s *.rootc.c cfs.h fs.h init.h conf.h *.out *.m errstr.h
+	rm -f *.[$OS] *.root.s *.rootc.c cfs.h fs.h init.h conf.h reboot.h reboot.list *.out *.m errstr.h
 
 %.clean:V:
 	rm -f $stem.c [9bz]$stem [9bz]$stem.gz s[9bz]$stem boot$stem.* *.acid