lib/libbl[ao]cklist: Use LIB_PACKAGE

This avoids e.g. utilities or ssh depending on the full blocklist
package just because they link against libblocklist.

This change moves files between packages so, until we have a proper
policy on how to handle this in release/stable branches, it should
not be MFC'd.

MFC after:	never
Reviewed by:	bapt
Sponsored by:	https://www.patreon.com/bsdivy
Differential Revision:	https://reviews.freebsd.org/D53605

lib/libblacklist/Makefile

@@ -3,6 +3,8 @@ BLOCKLIST_DIR=${SRCTOP}/contrib/blocklist
 .PATH: ${BLOCKLIST_DIR}/lib ${BLOCKLIST_DIR}/include ${BLOCKLIST_DIR}/port
 
 PACKAGE=	blocklist
+LIB_PACKAGE=
+
 LIB=	blacklist
 SHLIB_MAJOR= 0
 

lib/libblocklist/Makefile

@@ -3,6 +3,8 @@ BLOCKLIST_DIR=${SRCTOP}/contrib/blocklist
 .PATH: ${BLOCKLIST_DIR}/lib ${BLOCKLIST_DIR}/include ${BLOCKLIST_DIR}/port
 
 PACKAGE=	blocklist
+LIB_PACKAGE=
+
 LIB=	blocklist
 SHLIB_MAJOR= 0