ooops, m4 is already part of the host tools

SVN-Revision: 15044

include/prereq-build.mk

@@ -148,7 +148,3 @@ endef
 $(eval $(call Require,getopt-extended, \
 	Please install an extended getopt version that supports --long \
 ))
-
-$(eval $(call RequireCommand,m4, \
-	Please install GNU m4 \
-))