Patch to link libcblas explicitly for LAPACK/Generic backend

Fixes build of opencv on sparc64

From Brad Smith

graphics/opencv/Makefile

@@ -8,6 +8,7 @@ V =			4.13.0
 GH_ACCOUNT =		opencv
 GH_PROJECT =		opencv
 GH_TAGNAME =		${V}
+REVISION-main =		0
 REVISION-java =		0
 
 PKGNAME-main =		opencv-${V}
@@ -25,7 +26,7 @@ SHARED_LIBS += $i 16.0
 .endfor
 
 WANTLIB-main += ${COMPILER_LIBCXX} OpenEXR-3_4 absl_hash absl_log_internal_message
-WANTLIB-main += avcodec avdevice avformat avif avutil c cairo gdk-3
+WANTLIB-main += avcodec avdevice avformat avif avutil c cairo cblas gdk-3
 WANTLIB-main += gdk_pixbuf-2.0 glib-2.0 gobject-2.0 gstapp-1.0 gstaudio-1.0
 WANTLIB-main += gstbase-1.0 gstpbutils-1.0 gstreamer-1.0 gstriff-1.0
 WANTLIB-main += gstvideo-1.0 gtk-3 jpeg lapack m openjp2 png protobuf

graphics/opencv/patches/patch-cmake_OpenCVFindLAPACK_cmake

@@ -0,0 +1,25 @@
+- cmake: link libcblas explicitly for LAPACK/Generic backend
+
+Index: cmake/OpenCVFindLAPACK.cmake
+--- cmake/OpenCVFindLAPACK.cmake.orig
++++ cmake/OpenCVFindLAPACK.cmake
+@@ -230,11 +230,18 @@ if(WITH_LAPACK)
+           find_path(CBLAS_INCLUDE_DIR "cblas.h")
+         endif()
+         if(CBLAS_INCLUDE_DIR AND LAPACKE_INCLUDE_DIR)
++          if(NOT DEFINED CBLAS_LIBRARY)
++            find_library(CBLAS_LIBRARY cblas)
++          endif()
++          set(_lapack_generic_libs "${LAPACK_LIBRARIES}")
++          if(CBLAS_LIBRARY)
++            list(APPEND _lapack_generic_libs "${CBLAS_LIBRARY}")
++          endif()
+           ocv_lapack_check(IMPL "LAPACK/Generic"
+             CBLAS_H "cblas.h"
+             LAPACKE_H "lapacke.h"
+             INCLUDE_DIR "${CBLAS_INCLUDE_DIR}" "${LAPACKE_INCLUDE_DIR}"
+-            LIBRARIES "${LAPACK_LIBRARIES}")
++            LIBRARIES "${_lapack_generic_libs}")
+         elseif(APPLE)
+           ocv_lapack_check(IMPL "LAPACK/Apple"
+             CBLAS_H "Accelerate/Accelerate.h"