[media] dvb-frontends: Make all DVB Frontends visible if COMPILE_TEST=y

Make the DVB Frontends menu visible when compile-testing, to allow
selecting additional drivers on top of the drivers that are already
automatically selected if MEDIA_SUBDRV_AUTOSELECT is enabled.

Without this, many drivers stay disabled during e.g. allmodconfig.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>