rsi: remove interface changes for AP mode

remove_interface callback of mac80211 is handled for AP mode.
Same is notified to firmware through vap_capabilities frame
with VAP status VAP_DELETE.

Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>