Revert: drm/i915: correctly order the ring init sequence

This reverts commit 57ecc93ce680b1ace1f9e79d588dabe32353202c which
really is commit 0d8957c8a90bbb5d34fab9a304459448a5131e06 upstream as it
has been reported to cause problems in the 3.4.y kernel series.

Reported-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Andreas Sturmlechner <andreas.sturmlechner@gmail.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Yang Guang <guang.a.yang@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>