drm/i915/gt: Remove reference to struct drm_device.pdev

References to struct drm_device.pdev should not be used any longer as
the field will be moved into the struct's legacy section. Add a fix
for the rsp commit.

v8:
	* fix commit message (Michael)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Fixes: a50ca39f ("drm/i915: setup the LMEM region")
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Cc: "Michał Winiarski" <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210429105101.25667-3-tzimmermann@suse.de