gxf: Add a local copy of the relevant parts of the frame rate table

gxf: Add a local copy of the relevant parts of the frame rate table

This avoids having to share this table across the library
boundaries.

This shared table used to be problematic, if always declaring
all exported data symbols with the dllimport attribute (even
while building that same library), since it needs to be a
link-time constant when it is used in AVCodec declarations
(in mpeg12enc.c).

Signed-off-by: Martin Storsjö <martin@martin.st>