Implement 'rd.timeout' to modify the device timeout

When generating units for devices the administrator might
want to use a different timeout than the default.
So implement a new parameter 'rd.timeout' for this.

References: bnc#878770

Signed-off-by: Hannes Reinecke <hare@suse.de>
Do not call 'lvm' for non-LVM device-mapper devices

If a device-mapper device is not created by LVM it's pointless
to call any 'lvm' programs got extract details; they'll be
failing anyway. So check the UUID before calling 'lvm'.
This speeds up initrd creation and avoids I/O errors on
multipath devices.

Signed-off-by: Hannes Reinecke <hare@suse.de>
90multipath: Load device_handler modules early during boot

The device handler modules need to be loaded early during boot
to avoid I/O errors being printed to the system log.

References: bnc#871617

Signed-off-by: Hannes Reinecke <hare@suse.de>