pkgconfig: Place the pkg.m4 into the main package

The pkg.m4 should be in the main package, the -dev package will attempt
to pull in X11 header files and will require too much filesystem space.

recipes-fixes/pkgconfig/pkgconfig_0.25.bbappend

@@ -0,0 +1,6 @@
+THISDIR := "${@os.path.dirname(bb.data.getVar('FILE', d, True))}"
+FILESPATH =. "${@base_set_filespath(["${THISDIR}/${PN}-${PV}"], d)}:"
+
+PRINC="1"
+
+FILES_${PN} += " ${datadir}/aclocal "