drm/i915/query: Align flavour of engine data lookup

Commit 750e76b4 ("drm/i915/gt: Move the [class][inst] lookup for
engines onto the GT") changed the engine query to iterate over uabi
engines but left the buffer size calculation look at the physical engine
count. Difference has no practical consequence but it is nicer to align
both queries.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 750e76b4 ("drm/i915/gt: Move the [class][inst] lookup for engines onto the GT")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@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/20191122104115.29610-1-tvrtko.ursulin@linux.intel.com


(cherry picked from commit 9acc99d8)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>