Line-in Mic support

[RaymdZ]

I realize that the internal mic is probably never going to work, and using Bluetooth earphone with mic is the easiest way.

But I found that the latest builds from @tctien342 support line-in mic (through 3.5mm wired earphone). For a more stable and secure usage, line-in is more preferable over the wireless one.

Would you also support that feature in your builds afterward?