Bluetooth: Add support for remote OOB input of P-256 data

The current management interface only allows to provide the remote
OOB input of P-192 data. This extends the command to also accept
P-256 data as well. To make this backwards compatible, the userspace
can decide to only provide P-192 data or the combined P-192 and P-256
data. It is also allowed to leave the P-192 data empty if userspace
only has the remote P-256 data.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>