kirkwood: use c-struct for access to SDRAM addr decode registers

kirkwood: use c-struct for access to SDRAM addr decode registers

Remove the defines and do this with a C-struct.

Signed-off-by: Holger Brunck <[email protected]>
cc: Prafulla Wadaskar <[email protected]>
cc: Valentin Longchamp <[email protected]>
cc: Gerlando Falauto <[email protected]>
cc: Marek Vasut <[email protected]>
Acked-By: Prafulla Wadaskar <[email protected]>