Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/gpu/drm/radeon/r600_cs.c b/drivers/gpu/drm/radeon/r600_cs.c
index 3324620..fd18be9 100644
--- a/drivers/gpu/drm/radeon/r600_cs.c
+++ b/drivers/gpu/drm/radeon/r600_cs.c
@@ -921,7 +921,7 @@
 		return 0;
 	ib = p->ib->ptr;
 	switch (reg) {
-	/* force following reg to 0 in an attemp to disable out buffer
+	/* force following reg to 0 in an attempt to disable out buffer
 	 * which will need us to better understand how it works to perform
 	 * security check on it (Jerome)
 	 */