Codesign fix for mac.

Followup on 07064c8.

Use codesign --deep to sign the .app before signing all the frameworks,
otherwise codesign will refuse to sign the app due to unsigned dylibs
when not making a static build.

The error is:

./visualboyadvance-m.app: code object is not signed at all
In subcomponent: ...libtheoraenc.1.dylib

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

src/wx/CMakeLists.txt

@@ -1222,7 +1222,7 @@ if(APPLE AND (UPSTREAM_RELEASE OR ENABLE_ONLINEUPDATES))
         add_custom_command(
             TARGET visualboyadvance-m
             POST_BUILD
-            COMMAND codesign --sign "Developer ID Application" --force ./visualboyadvance-m.app
+            COMMAND codesign --sign "Developer ID Application" --force --deep ./visualboyadvance-m.app
             WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
         )