media: pvrusb2: clean up unneeded complexity in pvrusb2 class logic

media: pvrusb2: clean up unneeded complexity in pvrusb2 class logic

The pvrusb2 driver struct class logic was dynamically creating a class
that should have just been static as it did not do anything special and
was only a wrapper around a stock "struct class" implementation.  Clean
this all up by making a static struct class and modifying the code to
correctly reference it.

By doing so, lots of unneeded lines of code were removed, and #ifdef
logic was cleaned up so that the .c files are not cluttered up with
extra complexity following the proper kernel coding style.

Cc: Mike Isely <isely@pobox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/20230329060132.2688621-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>