iommu/arm-smmu: Add support for active-only interconnect votes

The SMMU interconnect voting vote assumes all votes are required
in both the active and sleep contexts. This means that votes
for a particular interconnect path cast by the SMMU driver will
be upheld even when the CPU subsystem has been suspended, which
is not correct from a power consumption perspective.

Thus, add support for the qcom,active-only property to denote
that interconnect votes should be upheld only when the CPU
subsystem is in the active context.

Change-Id: I3168a9ff55809370e155771ab2b7918da06755e4
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>