drm/xe: Cleanup TRAILING_WHITESPACE style issues

Remove all existing style issues of type TRAILING_WHITESPACE reported
by checkpatch.

Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>