This patch creates a new include directory include/media, populates
it with a few files header files and fixups the affected drivers to
compile with the new directory layout.

The directory is intented to be used for (kernel-internal) header files
of the media drivers (which are sitting below drivers/media).  For now
the video-buf.h (mm helper), tuner.h (tv/radio tuner) and audiochip.h
(tv sound decoder drivers) header files are moved.  Some more header
files from the dvb folks will likely follow.