Simplified arch/arm/Makefile by dropping the maketools target
It was undocumented and not needed

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Michal Marek <mmarek@suse.cz>