drm/xe/pf: Allow to encode subset of VF configuration KLVs

We want to reuse format of the GuC KLVs while saving and restoring
VF configuration by the PF driver, but some of those KLVs (like
doorbell begin index or GGTT starting offset) are not strictly
needed to correctly restore VF configuration. Modify functions to
omit encoding of some of the KLVs with GuC only details.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240919171528.1451-4-michal.wajdeczko@intel.com