V4L/DVB (8149): Avermedia E506 composite

Composite was originally mis-labelled as name_comp1,
so it should be simply redone as name_comp,
with its now corrected attributes.

Signed-off-by: Tim Farrington <timf@iinet.net.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>