nl80211: prohibit mixing 'any' and regular wowlan triggers

nl80211: prohibit mixing 'any' and regular wowlan triggers

If the device supports waking up on 'any' signal - i.e. it continues
operating as usual and wakes up the host on pretty much anything that
happens, then it makes no sense to also configure the more restricted
WoWLAN mode where the device operates more autonomously but also in a
more restricted fashion.

Currently only cw2100 supports both 'any' and other triggers, but it
seems to be broken as it doesn't configure anything to the device, so
we can't currently get into a situation where both even can correctly
be configured. This is about to change (Intel devices are going to
support both and have different behaviour depending on configuration)
so make sure the conflicting modes cannot be configured.

(It seems that cw2100 advertises 'any' and 'disconnect' as a means of
saying that's what it will always do, but that isn't really the way
this API was meant to be used nor does it actually mean anything as
'any' always implies 'disconnect' already, and the driver doesn't
change device configuration in any way depending on the settings.)

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