drm/i915/bxt: add revision id for A1 stepping and use it

Prefer inclusive ranges for revision checks rather than "below B0". Per
specs A2 is not used, so revid <= A1 matches revid < B0.

Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1445343722-3312-2-git-send-email-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/intel_hdmi.c

@@ -2039,7 +2039,7 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 		 * On BXT A0/A1, sw needs to activate DDIA HPD logic and
 		 * interrupts to check the external panel connection.
 		 */
-		if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
+		if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) <= BXT_REVID_A1))
 			intel_encoder->hpd_pin = HPD_PORT_A;
 		else
 			intel_encoder->hpd_pin = HPD_PORT_B;