arm: mvebu: clearfog: document eMMC installation

Document build and install of U-Boot image on Clearfog with eMMC.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>
1 file changed