Bluetooth: HCI: Fix and extend advertising report events

The advertising report (standard or direct) events require
a number of reports field that is used by the controller
to fill in the structure.
At the same time this fixes the subevent code of the direct
advertising report structure.

Change-Id: I0fdb9b1dcad03615ac9b3f1f38fdfbe9ab3f9c3a
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>