The nodedev driver currently only detects harddisk, cdrom
and floppy devices. This adds support for SD cards, which
are common storage for ARM devices, eg the Google ChromeBook

<device>
  <name>block_mmcblk0_0xb1c7c08b</name>
  <parent>computer</parent>
  <capability type='storage'>
    <block>/dev/mmcblk0</block>
    <drive_type>sd</drive_type>
    <serial>0xb1c7c08b</serial>
    <size>15758000128</size>
    <logical_block_size>512</logical_block_size>
    <num_blocks>30777344</num_blocks>
  </capability>
</device>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>