install-ffmpeg-ios.sh: remove redundant configure options

While writing a documentation for FFmpeg build on iOS it was found that
many options are redundant. Remove them to simplify the provisioning
script and to reduce the amount of cargo cult code.

Fixes: QTBUG-133502
Change-Id: I26aab49365eaca83bcdbfeb86de0638ac701bb80
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
Reviewed-by: Jukka Jokiniva <jukka.jokiniva@qt.io>
(cherry picked from commit d7d7c522b6)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 999e66fb4a)

coin/provisioning/common/unix/install-ffmpeg-ios.sh

@@ -55,18 +55,12 @@ build_ffmpeg_ios() {
     --arch=$target_platform \
     --cc="xcrun --sdk ${target_sdk} clang -arch $target_platform" \
     --cxx="xcrun --sdk ${target_sdk} clang++ -arch $target_platform" \
-    --ar="$(xcrun --sdk ${target_sdk} --find ar)" \
-    --ranlib="$(xcrun --sdk ${target_sdk} --find ranlib)" \
-    --strip="$(xcrun --sdk ${target_sdk} --find strip)" \
-    --nm="$(xcrun --sdk ${target_sdk} --find nm)" \
     --target-os=darwin \
     --extra-ldflags="$minos" \
     --enable-cross-compile \
     --enable-shared \
     --disable-static \
     --install-name-dir='@rpath' \
-    --enable-swscale \
-    --enable-pthreads \
     --disable-audiotoolbox
 
     sudo make install DESTDIR="$build_dir/installed" -j4