opencv: Enable pkgconfig file HYP-22728

opencv 4.1 does not generate pkgconfig file opencv.pc.
See opencv/opencv#13154

Signed-off-by: Mario Schuknecht <mario.schuknecht@dresearch-fe.de>

recipes-support/opencv/opencv_4.1.0.bbappend

@@ -1,3 +1,7 @@
 # see http://stackoverflow.com/questions/36221909/why-am-i-getting-thumb-conditional-instruction-should-be-in-it-block-error
 
 EXTRA_OECMAKE_append_arm = " -DCMAKE_CXX_FLAGS_RELEASE="-Wa,-mimplicit-it=thumb" "
+
+# Generate pkgconfig file opencv.pc
+# See https://github.com/opencv/opencv/issues/13154
+EXTRA_OECMAKE_append = " -DOPENCV_GENERATE_PKGCONFIG=ON -DOPENCV_PC_FILE_NAME=opencv.pc"