configure.ac: export plugin description more platform independent
configure.ac: export plugin description more platform independent

Fixes #642504.

drothlis/gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,Lachann/gstreamer,Distrotech/gstreamer,cfoch/gstreamer,mparis/gstreamer,collects/gstreamer,justinjoy/gstreamer,ahmedammar/platform_external_gst_gstreamer,ensonic/gstreamer,justinjoy/gstreamer,drothlis/gstreamer,shelsonjava/gstreamer,cfoch/gstreamer,collects/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,cablelabs/gstreamer,krieger-od/gstreamer,ahmedammar/platform_external_gst_gstreamer,centricular/gstreamer,ahmedammar/platform_external_gst_gstreamer,cablelabs/gstreamer,ylatuya/gstreamer,StreamUtils/gstreamer,magcius/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,drothlis/gstreamer,Distrotech/gstreamer,collects/gstreamer,drothlis/gstreamer,jpakkane/gstreamer,mparis/gstreamer,Distrotech/gstreamer,ensonic/gstreamer,jpxiong/gstreamer,justinjoy/gstreamer,shelsonjava/gstreamer,jpakkane/gstreamer,cfoch/gstreamer,ahmedammar/platform_external_gst_gstreamer,justinjoy/gstreamer,surround-io/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,magcius/gstreamer,cablelabs/gstreamer,ahmedammar/platform_external_gst_gstreamer,StreamUtils/gstreamer,lubosz/gstreamer,krieger-od/gstreamer,collects/gstreamer,mparis/gstreamer,lovebug356/gstreamer,ylatuya/gstreamer,Lachann/gstreamer,lovebug356/gstreamer,magcius/gstreamer,cfoch/gstreamer,surround-io/gstreamer,ensonic/gstreamer,magcius/gstreamer,centricular/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,centricular/gstreamer,centricular/gstreamer,Lachann/gstreamer,cablelabs/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,lubosz/gstreamer,centricular/gstreamer,krieger-od/gstreamer,Lachann/gstreamer,lovebug356/gstreamer,justinjoy/gstreamer,StreamUtils/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,Lachann/gstreamer,mparis/gstreamer,ensonic/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,collects/gstreamer,lovebug356/gstreamer,cfoch/gstreamer,lubosz/gstreamer,ylatuya/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,jpakkane/gstreamer,drothlis/gstreamer,krieger-od/gstreamer,krieger-od/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,shelsonjava/gstreamer,krichter722/gstreamer,ylatuya/gstreamer,krichter722/gstreamer,magcius/gstreamer,lovebug356/gstreamer,Distrotech/gstreamer,ylatuya/gstreamer