Bluetooth: SDP: Partial resolved if no space for next SDP SSA discover

The minimum receiving buffer size is 0x0007. The following SDP
discovery should not be started if the space of the receiving buffer
is less than 0x0007.

If there is no more space of the receiving buffer for the next SDP SSA
discovery, try to notify the upper layer with the partial resolved.

Signed-off-by: Lyle Zhu <[email protected]>

Author: lylezhu2012