Revert "drm/i915/display/fbc: Disable fbc by default on TGL"

FBC can be re-enabled on TGL with WA of keeping it disabled
while PSR2 is enabled.

This reverts commit 2982ded2.
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201190406.1752-3-uma.shankar@intel.com

drivers/gpu/drm/i915/display/intel_fbc.c

@@ -1445,13 +1445,6 @@ static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
 	if (!HAS_FBC(dev_priv))
 		return 0;
 
-	/*
-	 * Fbc is causing random underruns in CI execution on TGL platforms.
-	 * Disabling the same while the problem is being debugged and analyzed.
-	 */
-	if (IS_TIGERLAKE(dev_priv))
-		return 0;
-
 	if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9)
 		return 1;