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/am3517_evm_defconfig b/configs/am3517_evm_defconfig
index 4eb4066..4c1f664 100644
--- a/configs/am3517_evm_defconfig
+++ b/configs/am3517_evm_defconfig
@@ -19,7 +19,7 @@
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_SYS_MALLOC=y
 CONFIG_SPL_SYS_MALLOC_SIZE=0x800000
-# CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR is not set
+# CONFIG_SPL_SYS_MMCSD_RAW_MODE is not set
 # CONFIG_SPL_FS_EXT4 is not set
 # CONFIG_SPL_I2C is not set
 CONFIG_SPL_MTD=y