drm/xe/pf: Don't show GGTT/LMEM debugfs files under media GT

Most of the PF's debugfs files (and their implementations) are
based on the GT hierarchy even if files are related to GGTT or
LMEM data, that are related to the tile.

While we could reach the tile data from any GT, to avoid potential
misuse, some functions allow to be used on the primary GT only,
and may use asserts to enforce that.

In our case, the following assert could be seen when reading the
/sys/kernel/debug/dri/0000:00:02.0/gt1/pf/ggtt_available

 [ ] xe 0000:00:02.0: [drm] Assertion `!xe_gt_is_media_type(gt)` failed!
 [ ] WARNING: CPU: 4 PID: 10609 at drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c:379 pf_get_spare_ggtt+0x256/0x4e0 [xe]
 [ ] RIP: 0010:pf_get_spare_ggtt+0x256/0x4e0 [xe]
 [ ] Call Trace:
 [ ]  <TASK>
 [ ]  xe_gt_sriov_pf_config_print_available_ggtt+0xb7/0x480 [xe]
 [ ]  ? __memcg_slab_post_alloc_hook+0x12f/0x3f0
 [ ]  xe_gt_debugfs_simple_show+0x7b/0xb0 [xe]
 [ ]  ? __pfx___drm_printfn_seq_file+0x10/0x10
 [ ]  ? __pfx___drm_puts_seq_file+0x10/0x10
 [ ]  seq_read_iter+0x139/0x4e0
 [ ]  seq_read+0x11d/0x160
 [ ]  full_proxy_read+0x6b/0xb0
 [ ]  vfs_read+0xfa/0x390

Fix that by moving GGTT/LMEM debugfs attributes to separate lists
and register them only when applicable (on primary GT, on DGFX).

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Tested-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Reviewed-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Link: https://lore.kernel.org/r/20250411193030.1865-1-michal.wajdeczko@intel.com