buildroot

busybox: security bump to version 1.24.2

The version bump doesn't inherently fix the security issues, however the
added CVE patches do, which fix:

CVE-2016-2147 - out of bounds write (heap) due to integer underflow in
udhcpc.
CVE-2016-2148 - heap-based buffer overflow in OPTION_6RD parsing.

Drop patches that are upstream as well.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>