wifi: cfg80211/mac80211: Add support to get radio index

wifi: cfg80211/mac80211: Add support to get radio index

Currently, per-radio attributes are set on per-phy basis, i.e., all the
radios present in a wiphy will take attributes values sent from user. But
each radio in a wiphy can get different values from userspace based on
its requirement.

To extend support to set per-radio attributes, add support to get radio
index from userspace. Add an NL attribute - NL80211_ATTR_WIPHY_RADIO_INDEX,
to get user specified radio index for which attributes should be changed.
Pass this to individual drivers, so that the drivers can use this radio
index to change per-radio attributes when necessary. Currently, per-radio
attributes identified are:
NL80211_ATTR_WIPHY_TX_POWER_LEVEL
NL80211_ATTR_WIPHY_ANTENNA_TX
NL80211_ATTR_WIPHY_ANTENNA_RX
NL80211_ATTR_WIPHY_RETRY_SHORT
NL80211_ATTR_WIPHY_RETRY_LONG
NL80211_ATTR_WIPHY_FRAG_THRESHOLD
NL80211_ATTR_WIPHY_RTS_THRESHOLD
NL80211_ATTR_WIPHY_COVERAGE_CLASS
NL80211_ATTR_TXQ_LIMIT
NL80211_ATTR_TXQ_MEMORY_LIMIT
NL80211_ATTR_TXQ_QUANTUM

By default, the radio index is set to -1. This means the attribute should
be treated as a global configuration. If the user has not specified any
index, then the radio index passed to individual drivers would be -1. This
would indicate that the attribute applies to all radios in that wiphy.

Signed-off-by: Roopni Devanathan <quic_rdevanat@quicinc.com>
Link: https://patch.msgid.link/20250615082312.619639-2-quic_rdevanat@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>