[media] dvb_ca_en50221: Fix wrong EXPORT_SYMBOL order

Some EXPORT_SYMBOL() on this file don't match the name of functions
that preceeds them.

Also, some kernel-doc markups also have a wrong name. Fix it.

Signed-off-by: Jasmin Jessich <jasmin@anw.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>