media: dvb/earth-pt1: fix wrong initialization for demod blocks

earth-pt1 driver was decomposed/restructured by the commit b732539e
("media: dvb: earth-pt1: decompose pt1 driver into sub drivers"),
but it introduced a problem regarding concurrent streaming:
Opening a new terrestial stream stops the reception of an existing,
already-opened satellite stream.

The demod IC in earth-pt1 boards contains 2 pairs of terr. and sat. blocks,
supporting 4 concurrent demodulations, and the above problem was because
the config of a terr. block contained whole reset/init of the pair blocks,
thus each open() of a terrestrial frontend wrongly cleared the config of
its peer satellite block of the demod.
This whole/pair reset should be executed earlier and not on each open().

Fixes: b732539e ("media: dvb: earth-pt1: decompose pt1 driver into sub drivers")

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>