drm/msm/sde: separate plane/encoder/crtc functions into headers

Currently, plane/encoder/crtc function prototypes reside in the
kms header. To improve code separation and reduce overlap changes,
separate plane/encoder/crtc functions from kms header into their
corresponding headers.

Change-Id: Id3a7098ada887538ac0635f381c553a516237e7a
Signed-off-by: Alan Kwong <akwong@codeaurora.org>
diff --git a/drivers/gpu/drm/msm/sde/sde_wb.h b/drivers/gpu/drm/msm/sde/sde_wb.h
index a2afc16..4e33595 100644
--- a/drivers/gpu/drm/msm/sde/sde_wb.h
+++ b/drivers/gpu/drm/msm/sde/sde_wb.h
@@ -17,6 +17,7 @@
 
 #include "msm_kms.h"
 #include "sde_kms.h"
+#include "sde_connector.h"
 
 /**
  * struct sde_wb_device - Writeback device context