This update for linuxrc fixes the following issues:

- Move plymouthd start after screen size detection. (bsc#1163115)
plymouthd is now started after the screen size detection for avoiding race
conditions with linuxrc. This is because the screen size detection might
potentially interfere with plymouthd as both linuxrc and plymouthd might
try to read from the same serial line.

- Iterate through the device list in sorted order. (bsc#1058039)
When searching for the installation repository, linuxrc iterates through
available local or network devices. As the devices were used in the order
they appeared in sysfs, it was more or less random.

This update was imported from the SUSE:SLE-15-SP1:Update update project.