[media] drivers: media: pci: Makefile: Remove duplicate subdirectory from obj-y

In the list of subdirectories compiled, b2c2/ appears twice.

This patch removes one of the appearances.

Signed-off-by: Andreas Ruprecht <rupran@einserver.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>