buildroot

hostapd: apply upstream security patches

This commit adds patches for three different upstream security advisories. No
CVE numbers stated.

http://w1.fi/security/2015-2/wps-upnp-http-chunked-transfer-encoding.txt
http://w1.fi/security/2015-3/integer-underflow-in-ap-mode-wmm-action-frame.txt
http://w1.fi/security/2015-4/eap-pwd-missing-payload-length-validation.txt

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>