dm: mmc: Allow disabling driver model in SPL

At present if U-Boot proper uses driver model for MMC, then SPL has to
also. While this is desirable, it places a significant barrier to moving
to driver model in some cases. For example, with a space-constrained SPL
it may be necessary to enable CONFIG_SPL_OF_PLATDATA which involves
adjusting some drivers.

Add new SPL versions of the options for DM_MMC, DM_MMC_OPS and BLK. By
default these follow their non-SPL versions, but this can be changed by
boards which need it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 82b8d75..51a87cd 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -30,6 +30,27 @@
 	  option will be removed as soon as all DM_MMC drivers use it, as it
 	  will the only supported behaviour.
 
+config SPL_DM_MMC
+	bool "Enable MMC controllers using Driver Model in SPL"
+	depends on SPL_DM && DM_MMC
+	default y
+	help
+	  This enables the MultiMediaCard (MMC) uclass which supports MMC and
+	  Secure Digital I/O (SDIO) cards. Both removable (SD, micro-SD, etc.)
+	  and non-removable (e.g. eMMC chip) devices are supported. These
+	  appear as block devices in U-Boot and can support filesystems such
+	  as EXT4 and FAT.
+
+config SPL_DM_MMC_OPS
+	bool "Support MMC controller operations using Driver Model in SPL"
+	depends on SPL_DM && DM_MMC_OPS
+	default y
+	help
+	  Driver model provides a means of supporting device operations. This
+	  option moves MMC operations under the control of driver model. The
+	  option will be removed as soon as all DM_MMC drivers use it, as it
+	  will the only supported behaviour.
+
 if MMC
 
 config SPL_MMC_TINY