synapticsmst: Fix crasher with MST flashing (#385)
synapticsmst: Fix crasher with MST flashing (#385)

b6f79556 caused the device ID strings to change, which synaptics
MST plugin was relying upon.

Update to use metadata instead to communicate this information.

hughsie/fwupd,vathpela/fwupd,hughsie/fwupd,superm1/fwupd,fwupd/fwupd,hughsie/fwupd,fwupd/fwupd,vathpela/fwupd,hughsie/fwupd,vathpela/fwupd,superm1/fwupd,fwupd/fwupd,superm1/fwupd,vathpela/fwupd,fwupd/fwupd