drm/xe/guc: Move GUC_ID_MAX definition to GuC ABI header

This macro represents GuC firmware capability and shall be defined
in the firmware ABI header. Move it to xe_guc_fwif.h file.

Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240313221112.1089-2-michal.wajdeczko@intel.com