Bluetooth: hci_event: Ignore reserved bits in LE Extended Adv Report

Broadcom controllers present on Apple Silicon devices use the upper
8 bits of the event type in the LE Extended Advertising Report for
the channel on which the frame has been received.
These bits are reserved according to the Bluetooth spec anyway such that
we can just drop them to ensure that the advertising results are parsed
correctly.

The following excerpt from a btmon trace shows a report received on
channel 37 by these controllers:

> HCI Event: LE Meta Event (0x3e) plen 55
      LE Extended Advertising Report (0x0d)
        Num reports: 1
        Entry 0
          Event type: 0x2513
            Props: 0x0013
              Connectable
              Scannable
              Use legacy advertising PDUs
            Data status: Complete
            Reserved (0x2500)
          Legacy PDU Type: Reserved (0x2513)
          Address type: Public (0x00)
          Address: XX:XX:XX:XX:XX:XX (Shenzhen Jingxun Software [...])
          Primary PHY: LE 1M
          Secondary PHY: No packets
          SID: no ADI field (0xff)
          TX power: 127 dBm
          RSSI: -76 dBm (0xb4)
          Periodic advertising interval: 0.00 msec (0x0000)
          Direct address type: Public (0x00)
          Direct address: 00:00:00:00:00:00 (OUI 00-00-00)
          Data length: 0x1d
          [...]
        Flags: 0x18
          Simultaneous LE and BR/EDR (Controller)
          Simultaneous LE and BR/EDR (Host)
        Company: Harman International Industries, Inc. (87)
          Data: [...]
        Service Data (UUID 0xfddf):
        Name (complete): JBL Flip 5

Signed-off-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>