drm/msm/sde: allow LUTDMA, DSI xin during secure transitions

Enable xin-id 7 corresponding to LUTDMA, DSI to be unblocked
in sui_block_xin_mask in sm6170. The  xin-mask defines
which xin-clients should be be blocked during secure-ui
session.

Change-Id: Iabdb2264eb6799061b9beeabedb4f8b447eafbcb
Signed-off-by: Raviteja Tamatam <travitej@codeaurora.org>