mmc: print SD/eMMC type for inited mmc devices

Depending on the boot priority, the eMMC/SD cards,
can be initialized with the same numbers for each boot.

To be sure which mmc device is SD and which is eMMC,
this info is printed by 'mmc list' command, when
the init is done.

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>