media: dib0700: remove orphan dvb_usb_dib0700_ir_proto declaration

The dvb_usb_dib0700_ir_proto has been removed by
commit 0ffd1ab3 ("V4L/DVB: dib0700: properly implement IR
change_protocol"), so remove the orphan declaration.

Link: https://lore.kernel.org/linux-media/20220920015902.785337-1-cuigaosheng1@huawei.com


Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>