media: frontends: fix ops get_algo()'s return type

The method dvb_frontend_ops::get_frontend_algo() is defined as
returning an 'enum dvbfe_algo', but the implementation in this
driver returns an 'int'.

Fix this by returning 'enum dvbfe_algo' on drivers.

[mchehab+samsung@kernel.org: merge similar patches and patch
 ddbridge-mci.c the same way]
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>