drm/i915/fbdev: Use fb->normal_view.gtt

Grab the GTT view for the fbdev fb pinning from
fb->normal_view.gtt instead of having and extra one on
the stack. Seems safer in case we ever put any new
information into normal GTT views.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250122151755.6928-6-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>