recipes: add missing pkgconfig class inherits

* These recipes all use pkg-config in some way but were missing
  dependencies on the tool, this patch adds them.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-gnome/recipes-connectivity/obex/obexd_0.48.bb

@@ -11,7 +11,7 @@ SRC_URI = "http://www.kernel.org/pub/linux/bluetooth/obexd-${PV}.tar.gz \
 SRC_URI[md5sum] = "d03cf9bad2983243837f4f6d76ef14a6"
 SRC_URI[sha256sum] = "eaa9d8d9542700e6750918d72a3ce00f8cf3a2771d3e2516efd1be5a05f78582"
 
-inherit autotools-brokensep
+inherit autotools-brokensep pkgconfig
 
 PACKAGES =+ "obex-client obex-plugins"
 

meta-gnome/recipes-gnome/desktop-file-utils/desktop-file-utils_0.18.bb

@@ -11,7 +11,7 @@ SRC_URI = "http://www.freedesktop.org/software/desktop-file-utils/releases/deskt
 SRC_URI[md5sum] = "d966b743eb394650f98d5dd56b9aece1"
 SRC_URI[sha256sum] = "d9449956c1c8caa75281a3322b2bb433db42610942f0ceeaa65ccd9636c04231"
 
-inherit autotools
+inherit autotools pkgconfig
 
 CACHED_CONFIGUREVARS += "ac_cv_prog_EMACS=no"
 

meta-gnome/recipes-gnome/libgtkstylus/libgtkstylus_0.5.bb

@@ -5,7 +5,7 @@ LICENSE = "LGPL-2.0+"
 LIC_FILES_CHKSUM = "file://tap.c;beginline=1;endline=20;md5=71756eeb144e9eeb177c69aa672b1635"
 PR = "r4"
 
-inherit autotools
+inherit autotools pkgconfig
 
 SRC_URI = "http://burtonini.com/temp/${PN}-${PV}.tar.gz \
     file://gtkstylus.sh"