mac80211: Add FILS discovery support

This patch adds mac80211 support to configure FILS discovery
transmission.
Changes include functions to store and retrieve FILS discovery
template, minimum and maximum packet intervals.

Signed-off-by: Aloka Dixit <alokad@codeaurora.org>
Link: https://lore.kernel.org/r/20200805011838.28166-3-alokad@codeaurora.org
[remove SUPPORTS_FILS_DISCOVERY, driver can just set wiphy info]
Link: https://lore.kernel.org/r/010101747a7b3cbb-6edaa89c-436d-4391-8765-61456d7f5f4e-000000@us-west-2.amazonses.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>