staging: greybus: fix block comment

This patch fix the coding style problem of block comment detected by the
checkpatch.pl.

WARNING: Block comments use a trailing */ on a separate line

Signed-off-by: Hisao Tanabe <[e-mail]>
Acked-by: Johan Hovold <[e-mail]>
Acked-by: Viresh Kumar <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/greybus/arche-apb-ctrl.c

···
 	 * Pasted from WDM spec,
 	 *  - A falling edge on POWEROFF_L is detected (a)
 	 *  - WDM enters standby mode, but no output signals are changed
-	 * */
+	 */
 
 	/* TODO: POWEROFF_L is input to WDM module  */
 	apb->state = ARCHE_PLATFORM_STATE_STANDBY;