win32u: Fix broken otmfsType flag generation.
Freetype uses a function to get the licensing flags, FT_Get_FSType_Flags(), and it's non-trivial. (See also: https://freetype.org/freetype2/docs/reference/ft2-information_retrieval.html#ft_get_fstype_flags) Use FF's function to get the proper flags, and then set otmfsType based on them.