No DISK devices reported on systems with RAID controllers

This is directly related to https://bugs.launchpad.net/checkbox/+bug/940249 and I give my apologies for not addressing this in the same merge request.

Servers systems which use a RAID controller as their main backing storage will have a DISK device with the ID_BUS value of 'cciss', as seen here:

P: /devices/pci0000:00/0000:00:0d.0/0000:03:00.0/cciss0/c0d0/block/cciss!c0d0
N: cciss/c0d0
W: 53
S: block/104:0
S: disk/by-id/cciss-3600508b1001030374541443833300300
S: disk/by-path/pci-0000:03:00.0
S: disk/by-id/wwn-0x600508b1001030374541443833300300
E: UDEV_LOG=3
E: DEVPATH=/devices/pci0000:00/0000:00:0d.0/0000:03:00.0/cciss0/c0d0/block/cciss!c0d0
E: MAJOR=104
E: MINOR=0
E: DEVNAME=/dev/cciss/c0d0
E: DEVTYPE=disk
E: SUBSYSTEM=block
E: ID_SCSI=1
E: ID_VENDOR=HP
E: ID_VENDOR_ENC=HP\x20\x20\x20\x20\x20\x20
E: ID_MODEL=LOGICAL_VOLUME
E: ID_MODEL_ENC=LOGICAL\x20VOLUME\x20\x20
E: ID_REVISION=2.74
E: ID_TYPE=disk
E: ID_SERIAL=3600508b1001030374541443833300300
E: ID_SERIAL_SHORT=600508b1001030374541443833300300
E: ID_WWN=0x600508b100103037
E: ID_WWN_VENDOR_EXTENSION=0x4541443833300300
E: ID_WWN_WITH_EXTENSION=0x600508b1001030374541443833300300
E: ID_SCSI_SERIAL=5001438007EAD830
E: ID_BUS=cciss
E: ID_PATH=pci-0000:03:00.0
E: ID_PART_TABLE_TYPE=dos
E: DEVLINKS=/dev/block/104:0 /dev/disk/by-id/cciss-3600508b1001030374541443833300300 /dev/disk/by-path/pci-0000:03:00.0 /dev/disk/by-id/wwn-0x600508b1001030374541443833300300

This needs to be addressed in the code of the udevadm parser as it only acknowledges 'ata' and 'scsi' devices at the moment.