P2P: Allow connection on 6 GHz channels if requested

P2P: Allow connection on 6 GHz channels if requested

Previously, 6 GHz channels were disabled for P2P operations. Use the new
allow_6ghz parameter with P2P_CONNECT, P2P_GROUP_ADD, and P2P_INVITE
commands for P2P connection on the 6 GHz channels when Wi-Fi Display is
enabled on both the devices.

However, the p2p_6ghz_disable parameter in the configuration takes a
higher precedence.

Indicate P2P 6 GHz band capable information in Device Capability Bitmap
of P2P Capability attribute to indicate the P2P Device is capable of P2P
operation in the 6 GHz band.

Signed-off-by: Sreeramya Soratkal <ssramya@codeaurora.org>