Bluetooth: Implement Set PHY Confguration command

This enables user to set phys which will be used in all subsequent
connections. Also host will use the same in LE scanning as well.

@ MGMT Command: Set PHY Configuration (0x0045) plen 4
        Selected PHYs: 0x7fff
          BR 1M 1SLOT
          BR 1M 3SLOT
          BR 1M 5SLOT
          EDR 2M 1SLOT
          EDR 2M 3SLOT
          EDR 2M 5SLOT
          EDR 3M 1SLOT
          EDR 3M 3SLOT
          EDR 3M 5SLOT
          LE 1M TX
          LE 1M RX
          LE 2M TX
          LE 2M RX
          LE CODED TX
          LE CODED RX
< HCI Command: LE Set Default PHY (0x08|0x0031) plen 3
        All PHYs preference: 0x00
        TX PHYs preference: 0x07
          LE 1M
          LE 2M
          LE Coded
        RX PHYs preference: 0x07
          LE 1M
          LE 2M
          LE Coded
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Default PHY (0x08|0x0031) ncmd 1
        Status: Success (0x00)
@ MGMT Event: Command Complete (0x0001) plen 3
      Set PHY Configuration (0x0045) plen 0
        Status: Success (0x00)
@ MGMT Event: PHY Configuration Changed (0x0026) plen 4
        Selected PHYs: 0x7fff
          BR 1M 1SLOT
          BR 1M 3SLOT
          BR 1M 5SLOT
          EDR 2M 1SLOT
          EDR 2M 3SLOT
          EDR 2M 5SLOT
          EDR 3M 1SLOT
          EDR 3M 3SLOT
          EDR 3M 5SLOT
          LE 1M TX
          LE 1M RX
          LE 2M TX
          LE 2M RX
          LE CODED TX
          LE CODED RX

Signed-off-by: Jaganath Kanakkassery <jaganathx.kanakkassery@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>