image-vmdk.bbclass: disable the NOISO = "1"

image-vmdk.bbclass: disable the NOISO = "1"

The vmdk needed hddimg which was generated by do_bootimg in the past,
but do_bootimg generated both iso and hddimg, so we set NOISO = "1",
it now uses do_bootdirectdisk, doesn't use do_bootimg anymore, so we
don't need NOISO = "1", and need remove it, otherwise:

IMAGE_FSTYPES += "live vmdk"

Would not generate the iso.

I'd like to remove it rather than comment it, but we had comment the
do_bootimg before.

(From OE-Core rev: c5c1517726aa103a3cdb60abda95e28997cac7c4)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>