spl: mmc: Try to clean up raw-mode options

Make the raw-mode options depend on SPL_SYS_MMCSD_RAW_MODE in a more
direct way. This makes it easier to understand the options with
'make menuconfig'.

There are three different ways of specifying the offset:

- sector offset
- partition number
- partition type

So make these a choice, so it is more obvious what is going on.

Update existing boards to enable SPL_SYS_MMCSD_RAW_MODE where needed.

Reviewed-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/imx93_var_som_defconfig b/configs/imx93_var_som_defconfig
index 94ce213..14f220e 100644
--- a/configs/imx93_var_som_defconfig
+++ b/configs/imx93_var_som_defconfig
@@ -45,6 +45,7 @@
 CONFIG_SPL_LOAD_IMX_CONTAINER=y
 CONFIG_IMX_CONTAINER_CFG="arch/arm/mach-imx/imx9/container.cfg"
 # CONFIG_SPL_SHARES_INIT_SP_ADDR is not set
+CONFIG_SPL_SYS_MMCSD_RAW_MODE=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR=0x1040
 CONFIG_SPL_I2C=y