drm/msm/sde: sde hw interrupt handling

Existing SDE HW interrupt was based on mdp/kms and is not
sufficient for supporting the SDE HW interrupt manipulation.
Changes are for enabling full SDE interrupt support and hiding
HAL interface implementation details from crtc/encoder.

Change-Id: I917a153d12bbb6b84758591ba69fe15181af7791
Signed-off-by: Ben Chan <bkchan@codeaurora.org>
Signed-off-by: Krishna Srinivas Kundurthi <kskund@codeaurora.org>