Add virtio-blk by-id rules based on 'serial' attribute

Add virtio-blk by-id rules based on 'serial' attribute

Using virtio-blk serial attributes add rules to extract drive serial numbers and
generate by-id links for the block device and partitions.

With these rules added, we now see the following symlinks in disk/by-id

% ls -al /dev/disk/by-id | grep vdb
lrwxrwxrwx. 1 root root   9 Jun  1 22:09 virtio-QM00001 -> ../../vda
lrwxrwxrwx. 1 root root  10 Jun  1 22:09 virtio-QM00001-part1 -> ../../vda1

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>