STA: Check driver capability to enable OCV when driver SME is used

STA: Check driver capability to enable OCV when driver SME is used

When the driver SME is used, offloaded RSN handshakes like SA Query, GTK
rekeying, FT authentication, etc. would fail if wpa_supplicant enables
OCV in initial connection based on configuration but the driver doesn't
support OCV. To avoid such failures check the driver's capability for
enabling OCV when the driver SME used.

This commit also adds a capability flag for indicating OCV support
by the driver.

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