We can drop the custom table.
For some reason, the interop does not accept GL_RGB_RAW_422_APPLE as
internal format for GL_RGB_422_APPLE, so switch the format table to use
GL_RGB (this way both interop and real textures work the same).
Another victim of the apparent requirement of exactly matching texture
formats is kCVPixelFormatType_32BGRA. vo_opengl wants to handle this as
normal RGBA texture, with a swizzle applied in the shader.
CGLTexImageIOSurface2D() rejects this, because it wants the exact
internal format. Just drop the format, because it's useless anyway.
(Maybe this is a bit too fragile...)
The code for copying a videotoolbox surface to mp_image was duplicated
(with some minor differences - I picked the hw_videotoolbox.c version,
because it was "better"). mp_imgfmt_from_cvpixelformat() is somewhat
duplicated with the vt_formats[] table, but this will be fixed in a
later commit, and moving the function to shared code is preparation.
