drm/msm/hdmi: add hdmi hdcp support (V3)

Add HDMI HDCP support including HDCP PartI/II/III authentication.
V1: Initial Change
V2: Address Bjorn&Rob's comments
    Refactor the authentication process to use single work instead
    of multiple work for different authentication stages.
V3: Update to align with qcom SCM api.

Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index 08ba8d0..331b291 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -9,6 +9,7 @@
 	select DRM_PANEL
 	select SHMEM
 	select TMPFS
+	select QCOM_SCM
 	default y
 	help
 	  DRM/KMS driver for MSM/snapdragon.