arm: imx: imx8m: soc: fix the macro name

arm: imx: imx8m: soc: fix the macro name

The function arch_spl_mmc_get_uboot_raw_sector() was never compiled,
even when the option CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION was
enabled. So rename the macro SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION to
CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION.

Fixes: 2a00d73d081a ("spl: mmc: Try to clean up raw-mode options")
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>