whisper : install shared libs when using GGML_BACKEND_DL (#3195)

ggml/src/CMakeLists.txt

@@ -224,7 +224,8 @@ function(ggml_add_backend_library backend)
         set_target_properties(${backend} PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
         target_compile_definitions(${backend} PRIVATE GGML_BACKEND_DL)
         add_dependencies(ggml ${backend})
-    else()
+        install(TARGETS ${backend} LIBRARY DESTINATION bin)
+   else()
         add_library(${backend} ${ARGN})
         target_link_libraries(ggml PUBLIC ${backend})
         install(TARGETS ${backend} LIBRARY)