disp: msm: set smmu cb domain attached during probe

Set the SMMU context-bank domain_attached flag and
the secure flag appropriately during MDP SMMU
context-bank probe as the mapping/attach is handled
by the SMMU driver during bootup.

Change-Id: I83c7a911d7e0d4986df7cc3e8975b6eb2720cec1
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>