Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index c9db49c1..8b63a69 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -676,7 +676,7 @@
 
 	early_init_dt_check_for_initrd(node);
 
-	/* Retreive command line */
+	/* Retrieve command line */
 	p = of_get_flat_dt_prop(node, "bootargs", &l);
 	if (p != NULL && l > 0)
 		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));