mwifiex: do not send regulatory update while starting AP

When regulatory domain changes, cfg80211 already issues request
to change regulatory domain to driver via reg_notifier.
There is no need to set regulatory again during start_ap.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Qingshui Gao <gaoqs@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>