package: proper aclocal fix

Revert r25827 and instead copy over the host aclocal files of the stuff
needed for auto* (libtool + pkgconfig). These logically belong with the
target stuff, as they are used for the target auto* toolchain.

Long term we should probably consider using
aclocal --acdir=$(STAGING_DIR)/usr/share/aclocal, so the host .m4 files
cannot interfere with the target build.