Remove uses of MODULE_DESCRIPTION(), MODULE_AUTHOR(), MODULE_LICENSE(),
etc., so that when reading the driver there is no doubt it is builtin-only.
The information is preserved in comments at the top of the file.
Replace module_platform_driver() with builtin_platform_driver(), which uses
the same init level priority, so init ordering is unchanged.
Note that MODULE_DEVICE_TABLE is a no-op for non-modular code.