Bluetooth: controller: Only allow supported feature bits to be set by host

Redefine mask of host-controlled feature bits to include only features
that are supported by the controller. This fixes a conformance test
failure where setting an unsupported host-controlled feature bit was
not rejected as it should.

Set the Connected Isochronous Streams (Host Support) bit from the host
only if unicast support is configured to avoid failures in
broadcast-only configurations.

Signed-off-by: Wolfgang Puffitsch <wopu@demant.com>