Bluetooth: HFP HF: SCO: Accept eSCO conn request

1. Accept the incoming Synchronous connection request and establish
a new sco connection object.
2. Enable sco conn complete in event_mask

> HCI Event: Connect Request (0x04) plen 10           [hci0] 126.198264
        Address: 48:9D:24:1F:4D:1D (BlackBerry RTS)
        Class: 0x7a020c
          Major class: Phone (cellular, cordless, payphone, modem)
          Minor class: Smart phone
          Networking (LAN, Ad hoc)
          Capturing (Scanner, Microphone)
          Object Transfer (v-Inbox, v-Folder)
          Audio (Speaker, Microphone, Headset)
          Telephony (Cordless telephony, Modem, Headset)
        Link type: eSCO (0x02)
< HCI Command: Accept Synchronous Co.. (0x01|0x0029) plen 21
        Address: 48:9D:24:1F:4D:1D (BlackBerry RTS)
        Transmit bandwidth: 8000
        Receive bandwidth: 8000
        Max latency: 7
        Setting: 0x0060
          Input Coding: Linear
          Input Data Format: 2's complement
          Input Sample Size: 16-bit
          # of bits padding at MSB: 0
          Air Coding Format: CVSD
        Retransmission effort: Optimize for power consumption (0x01)
        Packet type: 0x0006
          HV2 may be used
          HV3 may be used
> HCI Event: Command Status (0x0f) plen 4           [hci0] 126.205171
      Accept Synchronous Connection Request (0x01|0x0029) ncmd 1
        Status: Success (0x00)

Change-Id: I71597aef94e945a9c07be1960994ad20c1b44bb3
Signed-off-by: Sathish Narasimman <sathish.narasimman@intel.com>