msm: sde: move config validation earlier to stream on

Current configuration validation is performed when both
stream on is set and minimum buffers are queued. This is
too late for client application that queues buffer only in
commit phase. Since commit cannot fail, client application
cannot recover from configuration error. To support earlier
configuration validation in pre-commit phase, move configuration
validation to stream on state.

CRs-Fixed: 1102087
Change-Id: Id4541d7064d54e3bab8505c590cf624e58d111c1
Signed-off-by: Alan Kwong <akwong@codeaurora.org>