Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 05b7139..e74fa12 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -683,7 +683,7 @@
 #endif
 
 #ifdef CONFIG_PHYP_DUMP
-	/* scan tree to see if dump occured during last boot */
+	/* scan tree to see if dump occurred during last boot */
 	of_scan_flat_dt(early_init_dt_scan_phyp_dump, NULL);
 #endif
 
@@ -739,7 +739,7 @@
 
 	DBG("Scanning CPUs ...\n");
 
-	/* Retreive CPU related informations from the flat tree
+	/* Retrieve CPU related informations from the flat tree
 	 * (altivec support, boot CPU ID, ...)
 	 */
 	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);