spl: mmc: get rid of #ifdef CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION check

spl: mmc: get rid of #ifdef CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION check

Implement defaults for the raw partition image loading so that the #ifdef
CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION in spl_mmc_load_image() will no
longer be necessary.

This change makes it possible for mmc_load_image_raw_partition() and
mmc_load_image_raw_sector() to coexist.

Signed-off-by: Nikita Kiryanov <[email protected]>
Cc: Igor Grinberg <[email protected]>
Cc: Paul Kocialkowski <[email protected]>
Cc: Pantelis Antoniou <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Simon Glass <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Reviewed-by: Tom Rini <[email protected]>