media: dvb: Fix invocation of secure-demux when playing from TSIF

secure-demux processing function expects to receive a fixed
start address aligned to 4KB along with a read pointer, the
code provided the current address along with a read pointer
set to 0 as fixed value. This may cause the start address not
to be aligned to 4KB.

Change-Id: Ibd4a4c70c3b874df328de9d3fea0437cbdf53028
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>