Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/rtc/rtc-lpc32xx.c b/drivers/rtc/rtc-lpc32xx.c
index ec8701c..ae16250 100644
--- a/drivers/rtc/rtc-lpc32xx.c
+++ b/drivers/rtc/rtc-lpc32xx.c
@@ -240,7 +240,7 @@
 	spin_lock_init(&rtc->lock);
 
 	/*
-	 * The RTC is on a seperate power domain and can keep it's state
+	 * The RTC is on a separate power domain and can keep it's state
 	 * across a chip power cycle. If the RTC has never been previously
 	 * setup, then set it up now for the first time.
 	 */