package/luv: install libluv.pc.in

package/luv: install libluv.pc.in

Archive 1.30.1-0 doesn't contain libluv.pc.in which will break the build

Fixes:
 - http://autobuild.buildroot.org/results/5ec6b5a3622c343f7e401b7da7d4a1da15be2733

This issue has been fixed upstream in
https://github.com/luvit/luv/commit/946784fba047bcd275554b5040949e3d70994b30,
which should be in the next release.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Acked-by: Jörg Krause <joerg.krause@embedded.rocks>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>