media: ddbridge: move/reorder functions

The functions in ddbridge-core.c have been moved to different positions in
newer versions of the dddvb vendor driver package (most notably in version
0.9.9b). Perform the same code move to keep the diff of the upcoming
code bump simpler.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Tested-by: Richard Scobie <r.scobie@clear.net.nz>
Tested-by: Jasmin Jessich <jasmin@anw.at>
Tested-by: Dietmar Spingler <d_spingler@freenet.de>
Tested-by: Manfred Knick <Manfred.Knick@t-online.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>