drm/i915/gt: Rearrange ivb workarounds

Some rcs0 workarounds were being incorrectly applied to the GT, and so
we failed to restore the expected register settings after a reset.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210113225144.30810-2-chris@chris-wilson.co.uk