package/opencv3: bump version to 3.1.0

package/opencv3: bump version to 3.1.0

Removed patches applied upstream. This version bump is needed to
provide support for ffmpeg 3.0:
https://github.com/Itseez/opencv/commit/278747ba458c9097aa72bf664c7a8df96d3a56fa

Use BR2_PACKAGE_FFMPEG_AVRESAMPLE by default because OpenCV can use it
after
https://github.com/Itseez/opencv/commit/2b2e3ee93c6788b892b084cc04d0ead5ab75c197

Before this patch:
--     FFMPEG:                      YES
--       codec:                     YES (ver 57.24.103)
--       format:                    YES (ver 57.25.100)
--       util:                      YES (ver 55.17.103)
--       swscale:                   YES (ver 4.0.100)
--       resample:                  NO

After this patch:
--     FFMPEG:                      YES
--       codec:                     YES (ver 57.24.103)
--       format:                    YES (ver 57.25.100)
--       util:                      YES (ver 55.17.103)
--       swscale:                   YES (ver 4.0.100)
--       resample:                  YES (ver 3.0.0)

Disabled new options:
WITH_MATLAB, WITH_VA, WITH_VA_INTEL, DOWNLOAD_EXTERNAL_TEST_DATA

Removed obsolete option BUILD_opencv_hal

Removed options WITH_OPENGL & WITH_OPENMP from the "Disabled features"
block because they have their own ifeq-block later on.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>