VMX: Improve disk parse error for unknown values

VMX: Improve disk parse error for unknown values

Previously the error message showed the following:

error: internal error: Invalid or not yet handled value 'auto detect'
for VMX entry 'ide0:0.fileName'

This left the user unsure if it was a CD-ROM or a disk device that they
needed to fix. Now the error shows:

error: internal error: Invalid or not yet handled value 'auto detect'
for VMX entry 'ide0:0.fileName' for device type 'cdrom-raw'

Which should hopefully make it easier to see the issue with the VMX
configuration.