RELEASEDIR was removed in FreeBSD 9.x, at the same time /boot/loader

stopped using kgzip in the release process. We no longer need to build
kgzip as a cross tool, and tests for RELEASEDIR are obsolete, so
remove both.

Differential Revision: https://reviews.freebsd.org/D2313

Makefile.inc1

@@ -1469,12 +1469,9 @@ _btxld=		usr.sbin/btxld
 .endif
 .endif
 .if ${TARGET_ARCH} != ${MACHINE_ARCH}
-.if ${MK_RESCUE} != "no" || defined(RELEASEDIR)
+.if ${MK_RESCUE} != "no"
 _crunchide=	usr.sbin/crunch/crunchide
 .endif
-.if ${TARGET_ARCH} == "i386" && defined(RELEASEDIR)
-_kgzip=		usr.sbin/kgzip
-.endif
 .endif
 
 # If we're given an XAS, don't build binutils.
@@ -1520,7 +1517,6 @@ cross-tools: .MAKE
     ${_cc} \
     ${_btxld} \
     ${_crunchide} \
-    ${_kgzip} \
     sys/boot/usb/tools
 	${_+_}@${ECHODIR} "===> ${_tool} (obj,depend,all,install)"; \
 		cd ${.CURDIR}/${_tool} && \