drm/i915: Remove superfluous hw_flags from mi_set_context()

Why have both hw_flags and flags, when just one will do?

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170322210350.6208-1-chris@chris-wilson.co.uk


Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>