wifi: Add Mobile Hotspot(MHS) info callback

The info includes AP's frequency, bandwidth
and generation(operational mode).

Bug: 163288112
Test: Manuel Test. Hotspot works normally.
Test: atest VtsHalWifiHostapdV1_0TargetTest
Test: atest VtsHalWifiHostapdV1_1TargetTest
Test: atest VtsHalWifiHostapdV1_2TargetTest
Change-Id: I5ff640169f10178fac196d17cadbfeedd2787fc0