Without DT aliases, the numbering of mmc interfaces is unpredictable.
Adding them makes it possible to refer to devices consistently.  The
popular suggestion to use UUIDs obviously doesn't work with a blank
device fresh from the factory.

See commit fa2d0aa9 ("mmc: core: Allow setting slot index via
device tree alias") for more discussion.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>