configure: cleanup libiec61883 code, allow enabling via command line

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

configure

@@ -180,6 +180,7 @@ External library support:
   --enable-libfaac         enable FAAC support via libfaac [no]
   --enable-libfreetype     enable libfreetype [no]
   --enable-libgsm          enable GSM support via libgsm [no]
+  --enable-libiec61883     enable iec61883 via libiec61883 [no]
   --enable-libilbc         enable iLBC de/encoding via libilbc [no]
   --enable-libmodplug      enable ModPlug via libmodplug [no]
   --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
@@ -1055,6 +1056,7 @@ CONFIG_LIST="
     libfaac
     libfreetype
     libgsm
+    libiec61883
     libilbc
     libmodplug
     libmp3lame
@@ -1677,7 +1679,7 @@ dshow_indev_deps="IBaseFilter"
 dshow_indev_extralibs="-lpsapi -lole32 -lstrmiids -luuid"
 dv1394_indev_deps="dv1394 dv_demuxer"
 fbdev_indev_deps="linux_fb_h"
-iec61883_indev_deps="iec61883"
+iec61883_indev_deps="libiec61883"
 jack_indev_deps="jack_jack_h sem_timedwait"
 lavfi_indev_deps="avfilter"
 libcdio_indev_deps="libcdio"
@@ -3286,7 +3288,7 @@ enabled avisynth   && require2 vfw32 "windows.h vfw.h" AVIFileInit -lavifil32
 enabled fontconfig && require_pkg_config fontconfig "fontconfig/fontconfig.h" FcInit
 enabled frei0r     && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
 enabled gnutls     && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
-enabled iec61883   && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
+enabled libiec61883 && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
 enabled libaacplus && require  "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
 enabled libass     && require_pkg_config libass ass/ass.h ass_library_init
 enabled libbluray  && require libbluray libbluray/bluray.h bd_open -lbluray
@@ -3671,6 +3673,7 @@ echo "libcelt enabled           ${libcelt-no}"
 echo "libdc1394 support         ${libdc1394-no}"
 echo "libfaac enabled           ${libfaac-no}"
 echo "libgsm enabled            ${libgsm-no}"
+echo "libiec61883 support       ${libiec61883-no}"
 echo "libilbc enabled           ${libilbc-no}"
 echo "libmodplug enabled        ${libmodplug-no}"
 echo "libmp3lame enabled        ${libmp3lame-no}"