[POWERPC] Spelling fixes: arch/ppc/

Spelling fixes in arch/ppc/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc/syslib/ppc403_pic.c b/arch/ppc/syslib/ppc403_pic.c
index 607ebd1..c3b7b8b 100644
--- a/arch/ppc/syslib/ppc403_pic.c
+++ b/arch/ppc/syslib/ppc403_pic.c
@@ -112,7 +112,7 @@
 
 	/*
 	 * Disable all external interrupts until they are
-	 * explicity requested.
+	 * explicitly requested.
 	 */
 	ppc_cached_irq_mask[0] = 0;