Add openssh-sftp-server

[sparkleholic]

:Release Notes: Add openssh-sftp-server for the files transfotation through sftp

:Detailed Notes: QtCreator copies the files via sftp by default, and sftp-server should handle the sftp connection request on the target platform. For running sftp-server when it gets the sftp connection, dropbear(sshd) should know where the sftp-server executable exists.

:Testing Performed: SFTP File Transfotation OK

Local Test OK Build OK

:QA Notes: None

:Issues Addressed: None

[flowergom]

@hongsukil please review this PR.