VMX: Add cdrom-raw dev type from VMWare Fusion

VMX: Add cdrom-raw dev type from VMWare Fusion

According to VMWare's documentation 'cdrom-raw' is an acceptable value
for deviceType for a CD-ROM drive. The documentation states that the VMX
configuration for a CD-ROM deviceType is as follows:

ide|scsi(n):(n).deviceType = "cdrom-raw|atapi-cdrom|cdrom-image"

From the documentation it appears the following is true:
- cdrom-image = Provides the ISO to the VM
- atapi-cdrom = Provides a NEC emulated ATAPI CD-ROM on top of the host
  CD-ROM
- cdrom-raw = Passthru for a host CD-ROM drive. Allows CD-R burning from
  within the guest.

A CD-ROM prior to this patch would always provide an 'atapi-cdrom' is
modeled as:
  <disk type='block' device='cdrom'>
    <source dev='/dev/scd0'/>
    <target dev='hda' bus='ide'/>
    <address type='drive' controller='0' bus='0' target='0' unit='0'/>
  </disk>

This patch allows the 'device' attribute to be set to 'lun' for a raw
acccess CD-ROM such as:
  <disk type='block' device='lun'>
    <source dev='/dev/scd0'/>
    <target dev='hda' bus='ide'/>
    <address type='drive' controller='0' bus='0' target='0' unit='0'/>
  </disk>