Fix shared library suffix on OSX

sdl2-config.cmake.in

@@ -22,18 +22,18 @@ if(NOT TARGET SDL2::SDL2)
   set_target_properties(SDL2::SDL2 PROPERTIES
     INTERFACE_INCLUDE_DIRECTORIES "@includedir@/SDL2"
     IMPORTED_LINK_INTERFACE_LANGUAGES "C"
-    IMPORTED_LOCATION "@libdir@/libSDL2.so"
+    IMPORTED_LOCATION "@libdir@/${CMAKE_SHARED_LIBRARY_PREFIX}SDL2${CMAKE_SHARED_LIBRARY_SUFFIX}"
     INTERFACE_LINK_LIBRARIES "${SDL2_EXTRA_LINK_FLAGS}")
 
   add_library(SDL2::SDL2-static STATIC IMPORTED)
   set_target_properties(SDL2::SDL2-static PROPERTIES
     INTERFACE_INCLUDE_DIRECTORIES "@includedir@/SDL2"
     IMPORTED_LINK_INTERFACE_LANGUAGES "C"
-    IMPORTED_LOCATION "@libdir@/libSDL2.a"
+    IMPORTED_LOCATION "@libdir@/${CMAKE_STATIC_LIBRARY_PREFIX}SDL2${CMAKE_STATIC_LIBRARY_SUFFIX}"
     INTERFACE_LINK_LIBRARIES "${SDL2_EXTRA_LINK_FLAGS_STATIC}")
 
   add_library(SDL2::SDL2main STATIC IMPORTED)
   set_target_properties(SDL2::SDL2main PROPERTIES
     IMPORTED_LINK_INTERFACE_LANGUAGES "C"
-    IMPORTED_LOCATION "@libdir@/libSDL2main.a")
+    IMPORTED_LOCATION "@libdir@/${CMAKE_STATIC_LIBRARY_PREFIX}SDL2main${CMAKE_STATIC_LIBRARY_SUFFIX}")
 endif()