diag: Split data stream for User PDs on LPASS

The patch segregates different PD data onto separate buffers
and then onto its own data stream. The patch also adds a way
to configure data streams for PD independent of which peripheral
it resides on.

CRs-Fixed: 2019189
Change-Id: I09c4e1a7da0ccd3ba3e025e9f13da0fbcb95f103
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>