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-multimedia/recipes-multimedia/dleyna/media-service-upnp_0.4.0.bb

@@ -11,7 +11,7 @@ SRC_URI = "git://github.com/01org/${BPN}.git"
 SRCREV = "1996ecbe4a06c95d22f7d958e32e3d28f7a4a2e9"
 S = "${WORKDIR}/git"
 
-inherit autotools
+inherit autotools pkgconfig
 
 do_install_append() {
     install -d ${D}${bindir}

meta-multimedia/recipes-multimedia/dleyna/renderer-service-upnp_0.3.0.bb

@@ -11,7 +11,7 @@ SRC_URI = "git://github.com/01org/${BPN}.git"
 SRCREV = "4a0b1d7cd8e22d3cb0e09c77c344ceccbcbbd34f"
 S = "${WORKDIR}/git"
 
-inherit autotools
+inherit autotools pkgconfig
 
 do_install_append() {
     install -d ${D}${bindir}

meta-multimedia/recipes-multimedia/musicpd/libmpd_11.8.17.bb

@@ -8,4 +8,4 @@ SRC_URI = "http://www.musicpd.org/download/${PN}/${PV}/${PN}-${PV}.tar.gz"
 SRC_URI[md5sum] = "5ae3d87467d52aef3345407adb0a2488"
 SRC_URI[sha256sum] = "fe20326b0d10641f71c4673fae637bf9222a96e1712f71f170fca2fc34bf7a83"
 
-inherit autotools
+inherit autotools pkgconfig