This patch is extending the root device hints to also look at
ID_WWN_WITH_EXTENSION and ID_WWN_VENDOR_EXTENSION from udev.
Prior to this patch the IPA ramdisk only cared about ID_WWN but in some
systems in some platforms with a RAID controller, this ID can be same
even if they are different disks (see bug 1516641).
Closes-Bug: #1516641
Change-Id: Ic3e9a1111dfcc99702190c173562a0dccf5f94c4