demux: set ciplus input source [1/1]

demux: set ciplus input source [1/1]

PD#SWPL-23541

Problem:
For CAS project, AES descrambler can *NOT* worked
on dmx-1 and dmx-2

Solution:
On REE side, when set descrambler source, we also
need set ciplus input source. Secure OS descrambler
is responsible for set the ciplus output

Verify:
irdeto cas verify.

Signed-off-by: pengfei.liu <pengfei.liu@amlogic.com>
Change-Id: I05a7df887f8785418708c8384f0ff13de7d7b63e