[Tizen] Replace crosswalk-no-fatal-ld-warnings.patch with a gyp flag.

Since r262389 (r262093 in trunk) it is possible to disable fatal
warnings with a build system flag.

Do that instead of patching the code.
[Tizen] packaging: Stop installing libmojo_system.so.

Since r262728 (r260629) in trunk the build system respects the value of
the |component| gyp variable and produces a static library if it is not
set to "shared_library", just all other libraries.