V4L/DVB (12111): tcm825x: remove incorrect __exit_p wrapper

tcm825x_remove is not necessarily called on module exit, it can also be
called when the i2c_adapter is removed. While the i2c adapter might never
be removed on an embedded system, in practice this sensor driver can also
be used in e.g. a USB webcam where this is a perfectly acceptable thing
to do.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>