arm: socfpga: Enable SPL_DM_SEQ_ALIAS for all SOCFPGA configs

arm: socfpga: Enable SPL_DM_SEQ_ALIAS for all SOCFPGA configs

This feature is required in SPL to enable support for loading from SPI
flash.

Also clean up the #define in socfpga_common.h.

Signed-off-by: Nathan Rossi <[email protected]>
Reviewed-by: Stefan Roese <[email protected]>
Acked: Marek Vasut <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Chin-Liang See <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Stefan Roese <[email protected]>
Signed-off-by: Michal Simek <[email protected]>