makedepends: switch libmfx to intel-media-sdk

intel-media-sdk, the open source version of
intel-media-server-studio, has now reached an acceptable stable
release that can be used here to provide libmfx.

This brings 2 important results:

1) The experimental state can be removed from the Intel QSV
   support, since intel-media-sdk also provides libmfxhw64
   and plugins for hardware accelerated decode and encode.

2) Finally we can get rid of the unsecure rpath in ffmpeg
   binaries!

intel-media-sdk is now a makedepend, instead of an optdepend
as previously. If fact, I should have switched it to
intel-media-server-studio in optdepends some time ago when
it has changed to the open source version, but I letted this
way while waiting for an acceptable stable release of, which
taked a while to happen.

Users should remove the libmfx{-git} package and stay only with
intel-media-sdk{-git} package, since the former is the complete
solution with the dispatcher library (libmfx.a), libmfxhw64 and
plugins.

Note1:
------
For the proper use of Intel QSV in ffmpeg the user must set the
vaapi/libva driver to 'iHD' through the 'LIBVA_DRIVER_NAME'
environment variable. The 'iHD' vaapi/libva driver is provided by
intel-media-driver{-git} package, which at the current time is
already a dependency of intel-media-sdk{-git} package. Setting
the vaapi/libva driver to 'iHD' can be done, for example, by
uncommenting the proper line in '/etc/profile.d/intel-media.sh'.

Note2:
------
intel-media-sdk is currently at a pre-release state. This can
lead to bugs when using Intel QSV.

Note3:
------
Not all Intel platforms are supported by intel-media-sdk. At the
current time, it claims to support only 5th and 6th Generation
Intel® Core™ processors (Broadwell and Skylake). For details,
please see the MediaSDK and media-driver documentation:
- https://github.com/Intel-Media-SDK/MediaSDK/
- https://github.com/intel/media-driver/

Note4:
------
Intel QSV is available in x86_64 systems only.

Also in this commit:
--------------------
- depends: moved 'libbs2b' and 'sndio' from the AUR section to
  the official repositories section, since they are now at the
  [community] official repository.

.SRCINFO

@@ -1,7 +1,7 @@
 pkgbase = ffmpeg-full
 	pkgdesc = Record, convert and stream audio and video (all possible features including nvenc, qsv and libfdk-aac)
 	pkgver = 3.4.2
-	pkgrel = 5
+	pkgrel = 6
 	url = http://www.ffmpeg.org/
 	arch = i686
 	arch = x86_64
@@ -9,7 +9,6 @@ pkgbase = ffmpeg-full
 	makedepends = nasm
 	makedepends = opencl-headers
 	makedepends = blackmagic-decklink-sdk
-	makedepends = libmfx
 	depends = glibc
 	depends = alsa-lib
 	depends = jack
@@ -22,6 +21,7 @@ pkgbase = ffmpeg-full
 	depends = ladspa
 	depends = libass
 	depends = libbluray
+	depends = libbs2b
 	depends = libcaca
 	depends = celt
 	depends = libcdio-paranoia
@@ -70,6 +70,7 @@ pkgbase = ffmpeg-full
 	depends = opencl-icd-loader
 	depends = mesa
 	depends = openssl
+	depends = sndio
 	depends = sdl2
 	depends = libx11
 	depends = zlib
@@ -78,13 +79,11 @@ pkgbase = ffmpeg-full
 	depends = libdrm
 	depends = libvdpau
 	depends = chromaprint-fftw
-	depends = libbs2b
 	depends = flite1-patched
 	depends = libilbc
 	depends = kvazaar
 	depends = openh264
 	depends = libopenmpt-svn
-	depends = sndio
 	depends = shine
 	depends = vo-amrwbenc
 	depends = xavs
@@ -125,8 +124,8 @@ pkgbase = ffmpeg-full
 	sha256sums = 04a7176400907fd7db0d69116b99de49e582a6e176b3bfb36a03e50a4cb26a36
 	depends_x86_64 = cuda
 	depends_x86_64 = nvidia-utils
-	optdepends_x86_64 = intel-media-sdk: for Intel QSV support (experimental)
 	makedepends_x86_64 = vmaf
+	makedepends_x86_64 = intel-media-sdk
 
 pkgname = ffmpeg-full