Handle onboard serial ports when parsing sysfs
Handle onboard serial ports when parsing sysfs

The device detection stopped if one of the sources reported at least
one device. This made onboard serial ports not listed if a USB device was
plugged in. Onboard serial ports are now detected and added to the list
of devices.

Change-Id: I8798e7f14073e19d9e206eb4d7cdd0b28bd8a0bb
Reviewed-by: Sergey Belyashov <8871b4c2d635fca691211507eadbac3d0bc2695a@gmail.com>
Reviewed-by: Denis Shienkov <6a9c747bd2ba446682324cf340d3b86f30cf4d55@gmail.com>

RoadWorksSoftware/QtSerialPort-OS2,RoadWorksSoftware/QtSerialPort-OS2