drm/i915: Make state dumpers take a const state

Constify a bunch of the arguments of various state dumping
functions. Makes it clear they don't mutate the states.
And fix up some indent fails while at it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190517193132.8140-13-ville.syrjala@linux.intel.com


Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>