pulseaudio: fix floating dependency on webrtc-audio-processing

The webrtc-audio-processing library isn't yet packaged for
OpenEmbedded, but let's add a packageconfig entry for it anyway to
avoid problems in the future.

(From OE-core rev: afcdc3d9d83cc72eb22c00160770282cd72dbca7)

Signed-off-by: Tanu Kaskinen <tanuk@iki.fi>
Signed-off-by: Ross Burton <ross.burton@intel.com>

meta/recipes-multimedia/pulseaudio/pulseaudio.inc

@@ -58,6 +58,7 @@ PACKAGECONFIG[jack] = "--enable-jack,--disable-jack,jack"
 # able to use pulseaudio autospawn for root as well.
 PACKAGECONFIG[autospawn-for-root] = ",,,"
 PACKAGECONFIG[lirc] = "--enable-lirc,--disable-lirc,lirc"
+PACKAGECONFIG[webrtc] = "--enable-webrtc-aec,--disable-webrtc-aec,webrtc-audio-processing"
 
 EXTRA_OECONF_append_arm = "${@bb.utils.contains("TUNE_FEATURES", "neon", "", " --enable-neon-opt=no", d)}"
 EXTRA_OECONF_append_armeb = "${@bb.utils.contains("TUNE_FEATURES", "neon", "", " --enable-neon-opt=no", d)}"