hostapd: fix broken WPS on broadcom-wl and ath11k

hostapd: fix broken WPS on broadcom-wl and ath11k

Upgrading wpa_supplicant from 2.9 to 2.10 breaks broadcom-wl/ath11k
based adapters. The reason for it is hostapd tries to install additional
IEs for scanning while the driver does not support this.

The kernel indicates the maximum number of bytes for additional scan IEs
using the NL80211_ATTR_MAX_SCAN_IE_LEN attribute. Save this value and
only add additional scan IEs in case the driver can accommodate these
additional IEs.

Bug: http://lists.infradead.org/pipermail/hostap/2022-January/040178.html
Bug-Debian: https://bugs.debian.org/1004524
Bug-ArchLinux: https://bugs.archlinux.org/task/73495
Upstream-Status: Changes Requested [https://patchwork.ozlabs.org/project/hostap/patch/20220130192200.10883-1-mail@david-bauer.net]
Reported-by: Étienne Morice <neon.emorice@mail.com>
Tested-by: Étienne Morice <neon.emorice@mail.com>
Signed-off-by: David Bauer <mail@david-bauer.net>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
(cherry picked from commit 6dca88aa4acd60229147628cb920d05a1136666d)