drivers: nrfwifi: Fix regulatory domain regression

Recent WPA supplicant changes have broken nRF regulatory support,
implement the new set/get country WPA supplicant ops.

WPA supplicant: Regulatory SET through WPA supplicant, GET is direct to
the driver

Scan only: SET and GET direct calls to the driver

Fixes #79916.

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>