dash: don't use board variable for recovery images

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
dash: no support for SABRE Lite

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
dash: no PCIE support

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
dash: max 1 disk of any type

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
dash: default IP address and netmask for USB networking

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>