drm/i915/glk: Fix DSI enable I/O sequence

One of the if statement covers the next line in enable I/O sequence.
This patch correct the same by adding error message.

Fixes: 4644848 ("drm/i915/glk: Add MIPIIO Enable/disable sequence")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1488393082-30660-1-git-send-email-madhav.chauhan@intel.com

drivers/gpu/drm/i915/intel_dsi.c

@@ -425,6 +425,7 @@ static void glk_dsi_device_ready(struct intel_encoder *encoder)
 		if (intel_wait_for_register(dev_priv,
 				MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE,
 				GLK_ULPS_NOT_ACTIVE, 20))
+			DRM_ERROR("ULPS is still active\n");
 
 		/* Exit ULPS */
 		val = I915_READ(MIPI_DEVICE_READY(port));