Bluetooth: host: Fallback to L2CAP for CPUP if rejected by master on LL

Fallback to L2CAP Connection Parameters Update Request if LL Connection
Update Request was rejected by remote device that has this marked as
supported in features. This can happen if procedure is supported only
by remote controller, but not enabled by host. This is connection
parameters update with iOS devices.

Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>