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-oe/recipes-devtools/icon-slicer/icon-slicer_0.3.bb

@@ -8,6 +8,6 @@ SRC_URI = "http://freedesktop.org/software/${BPN}/releases/${BPN}-${PV}.tar.gz \
 SRC_URI[md5sum] = "5c5374d4f265b0abe4daef1d03f87104"
 SRC_URI[sha256sum] = "05f0216dd0c25a17859de66357f64da5033375b6fbf5f31ca54867311160b64d"
 
-inherit autotools
+inherit autotools pkgconfig
 
 BBCLASSEXTEND = "native"

meta-oe/recipes-devtools/libgee/libgee.inc

@@ -9,7 +9,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=fbc093901857fcd118f065f900982c24"
 INC_PR = "r6"
 PE = "1"
 
-inherit autotools vala
+inherit autotools vala pkgconfig
 do_configure_prepend() {
     MACROS="libtool.m4 lt~obsolete.m4 ltoptions.m4 ltsugar.m4 ltversion.m4"
     for i in ${MACROS}; do

meta-oe/recipes-devtools/vala-dbus-binding-tool/vala-dbus-binding-tool.inc

@@ -11,6 +11,6 @@ export XDG_DATA_DIRS = "${STAGING_DATADIR}"
 
 SRC_URI = "http://downloads.freesmartphone.org/sources/${BPN}/${BP}.tar.bz2;name=archive"
 
-inherit autotools perlnative
+inherit autotools perlnative pkgconfig
 
 BBCLASSEXTEND = "native"