drm/i915: More stolen quirking

I've found a bios with an off-by-one at the other end. There's a pnp
reservation for 0xc5400000-0xc7fffffe and we want stolen in 0xc6000000
through 0xc8000000.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99872
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98683


Cc: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Martin Peres <martin.peres@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170719100043.30851-1-daniel.vetter@ffwll.ch