The Local Memory (aka VRAM) is only available on DGFX platforms.
We shouldn't attempt to provision VFs with LMEM or attempt to
update the LMTT on non-DGFX platforms. Add missing asserts that
would enforce that and fix release code that could crash on iGFX
due to uninitialized LMTT.

Fixes: c063cce7 ("drm/xe/pf: Update the LMTT when freeing VF GT config")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240607153155.1592-1-michal.wajdeczko@intel.com