Bluetooth: controller: Add scan response data setting restrictions

This adds restrictions for setting scan response data as specified by
Core spec:
* on legacy, only complete data can be set
* on legacy, data cannot be longer than 31 octets
* on ext, if non-scannable, data can only be discarded
* if ext enabled, only complete data can be set
* if ext enabled, data cannot be discarded

Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@codecoup.pl>