drm/i915: Don't require dev->struct_mutex in psr_match_conditions
Since I've reworked psr support to no longer require x-tiling we don't
check any state protected by the Giant GEM Lock. So drop that check.
Also boo for lockdep_assert_held for not yelling when lockdep is
disabled.
Cc: Paulo Zanoni <przanoni@gmail.com> Reported-by: Paulo Zanoni <przanoni@gmail.com> Acked-by: Paulo Zanoni <przanoni@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>