Revert "Let qtserialport load libudev at runtime"

This reverts commit de1006efdf200dcc68d58772fdfc8980409ddc6a.

d97a152bf14cd7b58e576bd6b4a5f304527f940e in QtSerialPort got it right.

Change-Id: I97cc9fa3de7a3742152b40c1cc16c9363b5d0169
Reviewed-by: Kai Koehne <kai.koehne@digia.com>