drm/vmwgfx: Fix kernel-doc warnings for vmwgfx_fence

drm/vmwgfx: Fix kernel-doc warnings for vmwgfx_fence

Add missing descriptions for vmw_event_fence_action_seq_passed.

This fixes the following warnings:
drivers/gpu/drm/vmwgfx/vmwgfx_fence.c:526 function parameter 'f'
	not described in 'vmw_event_fence_action_seq_passed'
drivers/gpu/drm/vmwgfx/vmwgfx_fence.c:526 function parameter 'cb'
	not described in 'vmw_event_fence_action_seq_passed'

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507040807.jKTxWGVQ-lkp@intel.com/
Signed-off-by: Bartlomiej Kubik <kubik.bartlomiej@gmail.com>
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://lore.kernel.org/all/20251211181044.4098689-1-kubik.bartlomiej@gmail.com/