build: add .pc file for Banshee.NotificationArea extension
build: add .pc file for Banshee.NotificationArea extension

This is needed by the new SongKickGeoLocation extension in b-c-e.

GNOME/banshee,GNOME/banshee,Carbenium/banshee,arfbtwn/banshee,stsundermann/banshee,arfbtwn/banshee,GNOME/banshee,Carbenium/banshee,stsundermann/banshee,GNOME/banshee,ixfalia/banshee,ixfalia/banshee,Carbenium/banshee,babycaseny/banshee,babycaseny/banshee,stsundermann/banshee,ixfalia/banshee,arfbtwn/banshee,babycaseny/banshee,stsundermann/banshee,stsundermann/banshee,Carbenium/banshee,arfbtwn/banshee,arfbtwn/banshee,ixfalia/banshee,ixfalia/banshee,Carbenium/banshee,stsundermann/banshee,GNOME/banshee,babycaseny/banshee,stsundermann/banshee,Carbenium/banshee,arfbtwn/banshee,stsundermann/banshee,babycaseny/banshee,GNOME/banshee,GNOME/banshee,babycaseny/banshee,arfbtwn/banshee,babycaseny/banshee,ixfalia/banshee,ixfalia/banshee,arfbtwn/banshee,ixfalia/banshee,babycaseny/banshee,GNOME/banshee