wifi: cfg80211: validate PMSR measurement type data

wifi: cfg80211: validate PMSR measurement type data

PMSR request parsing accepts missing or duplicated measurement type
entries in NL80211_PMSR_REQ_ATTR_DATA.

Track whether one measurement type was already provided, reject a
second one immediately, and return an error if the request data block
contains no measurement type at all.

Fixes: 9bb7e0f24e7e7 ("cfg80211: add peer measurement with FTM initiator API")
Assisted-by: Codex:gpt-5.5
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
Link: https://patch.msgid.link/20260612133656.92900-2-enderaoelyther@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>