[FFmpeg-cvslog] configure: fix check for opencl

[Jun Zhao]

ffmpeg | branch: master | Jun Zhao <mypopydev at gmail.com> | Sat Jun  2 11:02:38 2018 +0800| [3769aafb7c9a1fdcd1c9099a8ed7ba1d876c0693] | committer: Jun Zhao

configure: fix check for opencl

add pkg-config support for opencl check.

Signed-off-by: Jun Zhao <mypopydev at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3769aafb7c9a1fdcd1c9099a8ed7ba1d876c0693
---

 configure | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/configure b/configure
index 625cfef2ff..473be31d7f 100755
--- a/configure
+++ b/configure
@@ -6135,7 +6135,8 @@ enabled openal            && { { for al_extralibs in "${OPENAL_LIBS}" "-lopenal"
                                die "ERROR: openal not found"; } &&
                              { test_cpp_condition "AL/al.h" "defined(AL_VERSION_1_1)" ||
                                die "ERROR: openal must be installed and version must be 1.1 or compatible"; }
-enabled opencl            && { check_lib opencl OpenCL/cl.h clEnqueueNDRangeKernel -Wl,-framework,OpenCL ||
+enabled opencl            && { check_pkg_config opencl OpenCL CL/cl.h clEnqueueNDRangeKernel ||
+                               check_lib opencl OpenCL/cl.h clEnqueueNDRangeKernel -Wl,-framework,OpenCL ||
                                check_lib opencl CL/cl.h clEnqueueNDRangeKernel -lOpenCL ||
                                die "ERROR: opencl not found"; } &&
                              { test_cpp_condition "OpenCL/cl.h" "defined(CL_VERSION_1_2)" ||