When building on Linux, prefer using the SDL2 config module

This is shipped by SDL2 itself, so it should be the preferred way
of finding it. Since SDL2 does not ship it in their Windows
development libraries, we still need to use the regular Find module.

CMakeLists.txt

@@ -16,7 +16,7 @@ include(FetchContent)
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
     message("Linux build detected!")
 
-    find_package(SDL2 REQUIRED)
+    find_package(SDL2 REQUIRED CONFIG)
 
     set(ENABLE_VULKAN TRUE)
     set(ENABLE_LINUX TRUE)

platforms/sdl/CMakeLists.txt

@@ -7,6 +7,14 @@ if(ENABLE_MACOS)
     set(EXTRA_SRC ${CMAKE_CURRENT_SOURCE_DIR}/sdl_metal.mm)
 endif()
 
+if(TARGET SDL2::Main)
+    set(EXTRA_LIBRARIES SDL2::Main)
+endif()
+
+if(TARGET SDL2::SDL2main)
+    set(EXTRA_LIBRARIES SDL2::SDL2main)
+endif()
+
 add_platform(
         SRC
         ${CMAKE_CURRENT_SOURCE_DIR}/file.cpp
@@ -17,9 +25,9 @@ add_platform(
         MACOSX_BUNDLE ON
         MACOSX_BUNDLE_INFO_PLIST "${CMAKE_CURRENT_SOURCE_DIR}/Info.plist.in"
         LINK_LIBRARIES
-        SDL2::Main
         Core
         GFXVulkan
+        SDL2::SDL2
         ${EXTRA_LIBRARIES}
 )