drm/xe: Fix freq kobject leak on sysfs_create_files failure

drm/xe: Fix freq kobject leak on sysfs_create_files failure

Ensure gt->freq is released when sysfs_create_files() fails
in xe_gt_freq_init(). Without this, the kobject would leak.
Add kobject_put() before returning the error.

Fixes: fdc81c43f0c1 ("drm/xe: use devm_add_action_or_reset() helper")
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
Reviewed-by: Alex Zuo <alex.zuo@intel.com>
Reviewed-by: Xin Wang <x.wang@intel.com>
Link: https://patch.msgid.link/20251114205638.2184529-2-shuicheng.lin@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>