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/radeon_state.c b/drivers/gpu/drm/radeon/radeon_state.c
index 4ae5a3d..92e7ea7 100644
--- a/drivers/gpu/drm/radeon/radeon_state.c
+++ b/drivers/gpu/drm/radeon/radeon_state.c
@@ -980,7 +980,7 @@
 	}
 
 	/* hyper z clear */
-	/* no docs available, based on reverse engeneering by Stephane Marchesin */
+	/* no docs available, based on reverse engineering by Stephane Marchesin */
 	if ((flags & (RADEON_DEPTH | RADEON_STENCIL))
 	    && (flags & RADEON_CLEAR_FASTZ)) {