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

This reverts 622ecb9a which is
commit 0d8957c8 upstream.

We may only start to set up the new register values after having
confirmed that the ring is truely off. Otherwise the hw might lose the
newly written register values. This is caught later on in the init
sequence, when we check whether the register writes have stuck.

Reported-by: 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>