Merge pull request #26501 from asmorkalov:as/external_kleidicv

Fixed KLEIDICV_SOURCE_PATH handling for external KleidiCV

cmake/OpenCVFindLibsPerf.cmake

@@ -165,6 +165,7 @@ endif(WITH_CLP)
 # --- ARM KleidiCV
 if(WITH_KLEIDICV)
   if(KLEIDICV_SOURCE_PATH AND EXISTS "${KLEIDICV_SOURCE_PATH}/adapters/opencv/CMakeLists.txt")
+    message(STATUS "Use external KleidiCV ${KLEIDICV_SOURCE_PATH}")
     set(HAVE_KLEIDICV ON)
   endif()
   if(NOT HAVE_KLEIDICV)
@@ -173,7 +174,5 @@ if(WITH_KLEIDICV)
     if(KLEIDICV_SOURCE_PATH)
       set(HAVE_KLEIDICV ON)
     endif()
-  else()
-    set(HAVE_KLEIDICV OFF)
   endif()
 endif(WITH_KLEIDICV)