imx6: inittab: Use login.sh wrapper so we can configure console password

In dc92917 there was introduced login.sh wrapper which allows
configuration of console passwords via UCI system ttylogin config
option.

Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/imx6/base-files/etc/inittab

@@ -1,4 +1,4 @@
 ::sysinit:/etc/init.d/rcS S boot
 ::shutdown:/etc/init.d/rcS K shutdown
-::askconsole:/bin/ash --login
-tty1::askfirst:/bin/ash --login
+::askconsole:/usr/libexec/login.sh
+tty1::askfirst:/usr/libexec/login.sh