package/bluez_utils: add missing host-pkgconf dependency

The configure script use pkg-config.

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Yegor Yefremov <yegorslists@googlemail.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>