drm/i915: Fix crtc_y assignment in intel_find_initial_plane_obj()

Let's set crtc_y to 0 instead of setting src_y twice.

Multiple assignments in one statement is a good way to hide bugs.
Please don't do that.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: be5651f2

 ("drm/i915: Update missing properties in find_initial_plane_obj")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447434973-12369-1-git-send-email-ville.syrjala@linux.intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>