drm/i915: Add more registers to the whitelist for mesa

These are additional registers needed for performance monitoring and
ARB_draw_indirect extensions in mesa.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76719


Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
[danvet: Squash in fixup from Brad requested by Ken.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>