drm/i915: Use INTEL_GEN everywhere

Coccinelle patch:

 @@
 identifier p;
 @@
 -INTEL_INFO(p)->gen
 +INTEL_GEN(p)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208130606.15556-12-tvrtko.ursulin@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180209215847.6660-1-chris@chris-wilson.co.uk
18 files changed