lcd4linux: Possibility added that the config can also be loaded from /tmp

lcd4linux: Possibility added that the config can also be loaded from /tmp

Until now, the configuration must be stored under '/etc/lcd4linux.conf'.
So that the configuration can also be changed dynamically, it makes
sense to store this under /tmp and load them from this directory.
The init script first checks whether there is a configuration under
'/etc/lcd4linux.conf' and only then does it try to find it under
'/tmp/lcd4linux.conf'. If there is no configuration, an error message
is shown.

Signed-off-by: Florian Eckert <redacted>