This commit changes Ironic deploy ramdisk to find out
the virtual media device by using labels instead of
looking at the model of block device. This helps in
finding out the device irrespective of the hardware.
Corresponding Ironic change is
If5b78d9af7048f2631d050ee5ce01ab7a67e2354.
Closes-Bug: #1429340
Change-Id: I5e8a706989bad13051eb47db0b1e762e6c672318
In preparation for enabling Dracut-based ramdisks, this change
factors out functionality that is common to both busybox and Dracut
ramdisks. Said functionality is moved to a ramdisk-base element
which is added as a dependency of the ramdisk element. ramdisk now
only contains the functionality specific to building busybox-based
ramdisks.
bp tripleo-juno-dracut-ramdisks
Change-Id: Iad2907c8be491c88727d87ed5e5a720e5beb66c3
