mwifiex: Avoid skipping WEP key deletion for AP

This patch fixes the issue specific to AP. AP is started with WEP
security and external station is connected to it. Data path works
in this case. Now if AP is restarted with WPA/WPA2 security,
station is able to connect but ping fails.

Driver skips the deletion of WEP keys if interface type is AP.
Removing that redundant check resolves the issue.

Fixes: e57f1734 ("mwifiex: add key material v2 support")
Signed-off-by: Ganapathi Bhat <gbhat@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>