drm/i915: Add missing kerneldoc parameters for huc_ucode_xfer

During the recent upheaval to uc, the parameters to huc_ucode_xfer
were changed, but the kerneldoc left behind.

drivers/gpu/drm/i915/intel_huc.c:128: warning: Function parameter or member 'huc_fw' not described in 'huc_ucode_xfer'
drivers/gpu/drm/i915/intel_huc.c:128: warning: Function parameter or member 'vma' not described in 'huc_ucode_xfer'
drivers/gpu/drm/i915/intel_huc.c:128: warning: Excess function parameter 'dev_priv' description in 'huc_ucode_xfer'

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180214104040.4532-1-chris@chris-wilson.co.uk