drm: Spelling s/sempahore/semaphore/

Fix misspellings of "semaphore".

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: Hamza Mahfooz <[e-mail]>
Acked-by: Rodrigo Vivi <[e-mail]>
Signed-off-by: Javier Martinez Canillas <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/8b054[e-mail]

drivers/gpu/drm/i915/i915_request.c

···
 	/*
 	 * If this or its dependents are waiting on an external fence
 	 * that may fail catastrophically, then we want to avoid using
-	 * sempahores as they bypass the fence signaling metadata, and we
+	 * semaphores as they bypass the fence signaling metadata, and we
 	 * lose the fence->error propagation.
 	 */
 	if (from->sched.flags & I915_SCHED_HAS_EXTERNAL_CHAIN)

drivers/gpu/drm/radeon/cik.c

···
  * @rdev: radeon_device pointer
  * @ring: radeon ring buffer object
  * @semaphore: radeon semaphore object
- * @emit_wait: Is this a sempahore wait?
+ * @emit_wait: Is this a semaphore wait?
  *
  * Emits a semaphore signal/wait packet to the CP ring and prevents the PFP
  * from running ahead of semaphore waits.

drivers/gpu/drm/radeon/r600.c

···
  * @rdev: radeon_device pointer
  * @ring: radeon ring buffer object
  * @semaphore: radeon semaphore object
- * @emit_wait: Is this a sempahore wait?
+ * @emit_wait: Is this a semaphore wait?
  *
  * Emits a semaphore signal/wait packet to the CP ring and prevents the PFP
  * from running ahead of semaphore waits.

include/drm/task_barrier.h

···
 
 /*
  * Reusable 2 PHASE task barrier (randevouz point) implementation for N tasks.
- * Based on the Little book of sempahores - https://greenteapress.com/wp/semaphores/
+ * Based on the Little book of semaphores - https://greenteapress.com/wp/semaphores/
  */