eud: Set pdev->id value to 0 and add set_mctrl() API

pdev->id is needed to reference port with serial core framework.
Also serial core framework assumes that set_mctrl() ops is must
to support. Hence add set_mctrl() API to avoid null pointer
related crash within serial core framework.

Change-Id: Ida4ec2622232b822f1100e9c4ce0e8d3bd0d29c9
Signed-off-by: Mayank Rana <mrana@codeaurora.org>