drm/i915/gen9+: Remove redundant power well state assert during enabling

drm/i915/gen9+: Remove redundant power well state assert during enabling

We check already for power wells that are unexpectedly on (or forced on)
during power well disabling. Those checks also account for other
power well requesters like KVMR or DEBUG. As such this check is
redundant, let's remove it to simplify things.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1499352040-8819-9-git-send-email-imre.deak@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>