AP: Check driver's capability to enable OCV when driver SME is used

AP: Check driver's capability to enable OCV when driver SME is used

When the driver SME is used, offloaded handshakes which need Operating
Channel Validation (OCV) such as SA Query procedure, etc. would fail if
hostapd enables OCV based on configuration but the driver doesn't
support OCV. To avoid this when driver SME is used, enable OCV from
hostapd only when the driver indicates support for OCV.

This commit also adds a capability flag to indicate whether driver SME
is used in AP mode.

Signed-off-by: Veerendranath Jakkam <vjakkam@codeaurora.org>