sh: Add ttySC* to securetty

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

fs/skeleton/etc/securetty

@@ -42,3 +42,7 @@ ttyAM1
 ttyAM2
 ttySC0
 ttySC1
+ttySC2
+ttySC3
+ttySC4
+ttySC5