restored OpenBLAS detection; fixed MKL's lapack header (#7921)

cmake/OpenCVFindLAPACK.cmake

@@ -12,20 +12,20 @@ if(WITH_LAPACK)
             set(LAPACK_INCLUDE_DIR  ${MKL_INCLUDE_DIRS})
             set(LAPACK_LIBRARIES    ${MKL_LIBRARIES}   )
             set(LAPACK_CBLAS_H      "mkl_cblas.h"      )
-            set(LAPACK_LAPACKE_H    "mkl_lapacke.h"    )
+            set(LAPACK_LAPACKE_H    "mkl_lapack.h"    )
             set(LAPACK_IMPL         "MKL")
         endif()
     endif()
-    #if(NOT LAPACK_LIBRARIES)
-    #    include(cmake/OpenCVFindOpenBLAS.cmake)
-    #    if(OpenBLAS_FOUND)
-    #        set(LAPACK_INCLUDE_DIR  ${OpenBLAS_INCLUDE_DIR} )
-    #        set(LAPACK_LIBRARIES    ${OpenBLAS_LIB}         )
-    #        set(LAPACK_CBLAS_H      "cblas.h"      )
-    #        set(LAPACK_LAPACKE_H    "lapacke.h"    )
-    #        set(LAPACK_IMPL         "OpenBLAS")
-    #    endif()
-    #endif()
+    if(NOT LAPACK_LIBRARIES)
+        include(cmake/OpenCVFindOpenBLAS.cmake)
+        if(OpenBLAS_FOUND)
+            set(LAPACK_INCLUDE_DIR  ${OpenBLAS_INCLUDE_DIR} )
+            set(LAPACK_LIBRARIES    ${OpenBLAS_LIB}         )
+            set(LAPACK_CBLAS_H      "cblas.h"      )
+            set(LAPACK_LAPACKE_H    "lapacke.h"    )
+            set(LAPACK_IMPL         "OpenBLAS")
+        endif()
+    endif()
     if(NOT LAPACK_LIBRARIES AND UNIX)
         include(cmake/OpenCVFindAtlas.cmake)
         if(ATLAS_FOUND)