hostapd: Update to version 2.8 (2019-04-21)

hostapd: Update to version 2.8 (2019-04-21)

This also syncs the configuration files with the default configuration
files, but no extra options are activated or deactivated.

The mesh patches were partially merged into hostapd 2.8, the remaining
patches were extracted from patchwork and are now applied by OpenWrt.
The patches still have open questions which are not fixed by the author.
They were taken from this page:
https://patchwork.ozlabs.org/project/hostap/list/?series=62725&state=*

The changes in 007-mesh-apply-channel-attributes-before-running-Mesh.patch
where first applied to hostapd, but later reverted in hostapd commit
3e949655ccc5 because they caused memory leaks.

The size of the ipkgs increase a bit (between 1.3% and 2.3%):

old 2018-12-02 (2.7):
283337 wpad-basic_2018-12-02-c2c6c01b-11_mipsel_24kc.ipk
252857 wpad-mini_2018-12-02-c2c6c01b-11_mipsel_24kc.ipk
417473 wpad-openssl_2018-12-02-c2c6c01b-11_mipsel_24kc.ipk
415105 wpad-wolfssl_2018-12-02-c2c6c01b-11_mipsel_24kc.ipk

new 2019-04-21 (2.8):
288264 wpad-basic_2019-04-21-63962824-1_mipsel_24kc.ipk
256188 wpad-mini_2019-04-21-63962824-1_mipsel_24kc.ipk
427475 wpad-openssl_2019-04-21-63962824-1_mipsel_24kc.ipk
423071 wpad-wolfssl_2019-04-21-63962824-1_mipsel_24kc.ipk

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
(cherry picked from commit 8af79550e6c280717660f66032d89d21007b15d2)