Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

arch/powerpc/kernel/prom.c

@@ -683,7 +683,7 @@ void __init early_init_devtree(void *params)
 #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 @@ void __init early_init_devtree(void *params)
 
 	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);