drm/i915: Manage HSW/BDW LCPLLs with the shared dpll interface

Manage the LCPLLs used with DisplayPort, so that all the HSW/BDW DPLLs
are managed by the shared dpll code.

v2: Introduce INTEL_DPLL_ALWAYS_ON flag to please state checker. (Ander)

v3: Initialize pll->flags in intel_shared_dpll_init(). (Ander)

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457451987-17466-13-git-send-email-ander.conselvan.de.oliveira@intel.com
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 50cc264..31f9aa0 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -992,17 +992,13 @@
 {
 	struct intel_shared_dpll *pll;
 
-	if (intel_encoder->type == INTEL_OUTPUT_HDMI ||
-	    intel_encoder->type == INTEL_OUTPUT_ANALOG) {
-		pll = intel_get_shared_dpll(intel_crtc, crtc_state,
-					    intel_encoder);
-		if (!pll)
-			DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
-					 pipe_name(intel_crtc->pipe));
-		return pll;
-	} else {
-		return true;
-	}
+	pll = intel_get_shared_dpll(intel_crtc, crtc_state,
+				    intel_encoder);
+	if (!pll)
+		DRM_DEBUG_DRIVER("failed to find PLL for pipe %c\n",
+				 pipe_name(intel_crtc->pipe));
+
+	return pll;
 }
 
 static bool