wifi: Add logic to create secondary interface for STA mode too.

Previously we introduced dynamic interface create/remove logic for
SAP interface where wlan.concurrent.interface was given first
preference for SAP interface.

Remove this preference and fallback to use the default order of
choosing interface names. Also add create/remove logic for secondary
interface in STA mode too.

Change-Id: Iec5c4492096327a18e67f5129736a9bd3c8533f0
CRs-Fixed: 2268421