drm/msm/sde: add support to select secure context bank

Add support in the sde plane component to select the secure context
bank based on the fb_mode plane property. This changes also sets the
correct hw settings for the secure plane src address.

CRs-Fixed: 2050484
Change-Id: Iacdfbb366b3ff56fcd5036fb9157547542095cde
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>