Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/ps3/ps3-sys-manager.c b/drivers/ps3/ps3-sys-manager.c
index d37c445..1b98367 100644
--- a/drivers/ps3/ps3-sys-manager.c
+++ b/drivers/ps3/ps3-sys-manager.c
@@ -80,7 +80,7 @@
  *
  * Currently all messages received from the system manager are either
  * (16 bytes header + 8 bytes payload = 24 bytes) or (16 bytes header
- * + 16 bytes payload = 32 bytes).  This knowlege is used to simplify
+ * + 16 bytes payload = 32 bytes).  This knowledge is used to simplify
  * the logic.
  */