When using "redfish-dell" as the management type, airshipctl throws an
error due to a missing case statement. This change fixes the regression
by re-adding "redfish-dell" as a remote type.
Change-Id: I8314a1e356d1bb3bb1705762bbeda1adf1db41d2
Signed-off-by: Drew Walters <andrew.walters@att.com>