drm/i915/psr: enable psr2 for y cordinate panels

Psr2 is enabled only for y cordinate panels.Once GTC (global time code)
is implemented,this restriction is removed so that psr2
can work on panels without y cordinate support.

v2: (Rodrigo)
- Move the check to intel_psr_match_conditions

v3: (Rodrigo)
- add return false

v4: rebase

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jim Bride <jim.bride@linux.intel.com>
Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Signed-off-by: Patil Deepti <deepti.patil@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484173710-3138-1-git-send-email-vathsala.nagaraju@intel.com

drivers/gpu/drm/i915/intel_psr.c

@@ -441,6 +441,15 @@ static bool intel_psr_match_conditions(struct intel_dp *intel_dp)
 		return false;
 	}
 
+	/*
+	 * FIXME:enable psr2 only for y-cordinate psr2 panels
+	 * After gtc implementation , remove this restriction.
+	 */
+	if (!dev_priv->psr.y_cord_support &&  dev_priv->psr.psr2_support) {
+		DRM_DEBUG_KMS("PSR2 disabled, panel does not support Y coordinate\n");
+		return false;
+	}
+
 	dev_priv->psr.source_ok = true;
 	return true;
 }