Conwise CW6622 seems to have a problem with the stored link key
commands so just mark it as broken.

< HCI Command: Read Local Supported Features (0x04|0x0003) plen 0
> HCI Event: Command Complete (0x0e) plen 12
    Read Local Supported Features (0x04|0x0003) ncmd 1
    status 0x00
    Features: 0xff 0x3e 0x85 0x38 0x18 0x18 0x00 0x00
< HCI Command: Read Local Version Information (0x04|0x0001) plen 0
> HCI Event: Command Complete (0x0e) plen 12
    Read Local Version Information (0x04|0x0001) ncmd 1
    status 0x00
    HCI Version: 2.0 (0x3) HCI Revision: 0x1f4
    LMP Version: 2.0 (0x3) LMP Subversion: 0x1f4
    Manufacturer: CONWISE Technology Corporation Ltd (66)
...
< HCI Command: Read Local Supported Commands (0x04|0x0002) plen 0
> HCI Event: Command Complete (0x0e) plen 68
    Read Local Supported Commands (0x04|0x0002) ncmd 1
    status 0x00
    Commands: 7fffef03cedfffffffffff1ff20ff8ff3f
...
< HCI Command: Read Stored Link Key (0x03|0x000d) plen 7
    bdaddr 00:00:00:00:00:00 all 1
> HCI Event: Command Complete (0x0e) plen 8
    Read Stored Link Key (0x03|0x000d) ncmd 1
    status 0x11 max 0 num 0
    Error: Unsupported Feature or Parameter Value
Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>