drivers: wifi: nxp: fix the wrong security type print of WPA2

For embedded supplicant case, when connects to WPA2 AP, driver will set
the key_mgmt to 'WLAN_KEY_MGMT_PSK | WLAN_KEY_MGMT_PSK_SHA256', as mfp
is default WIFI_MFP_OPTIONAL. Therefore, when using 'wifi status' to
get the security type, when the key_mgmt is 'WLAN_KEY_MGMT_PSK |
WLAN_KEY_MGMT_PSK_SHA256', the security type should be
'WIFI_SECURITY_TYPE_PSK'.

Signed-off-by: Maochen Wang <maochen.wang@nxp.com>