i965: Don't enable reset notification support on Gen4-5.
arekm reported that using Chrome with GPU acceleration enabled on GM45
triggered the hw_ctx != NULL assertion in brw_get_graphics_reset_status.
We definitely do not want to advertise reset notification support on
Gen4-5 systems, since it needs hardware contexts, and we never even
request a hardware context on those systems.
Cc: "10.1" <mesa-stable@lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75723
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>