STiH410: Add STi SDHCI driver

Add SDHCI host controller found on STMicroelectronics SoCs

On some ST SoCs, i.e. STiH407/STiH410, the MMC devices can live
inside a dedicated flashSS sub-system that provides an extend subset
of registers that can be used to configure the Arasan MMC/SD Host
Controller.

This means, that the SDHCI Arasan Controller can be configured to be
eMMC4.5 or 4.3 spec compliant.

W/o these settings the SDHCI will configure and use the MMC/SD
controller with limited features e.g. PIO mode, no DMA, no HS etc.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 01d1dbf..ea5ea08 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -299,6 +299,13 @@
 
 	  If unsure, say N.
 
+config MMC_SDHCI_STI
+	bool "SDHCI support for STMicroelectronics SoC"
+	depends on MMC_SDHCI
+	help
+	  This selects the Secure Digital Host Controller Interface (SDHCI)
+	  on STMicroelectronics STiH410 SoC.
+
 config MMC_SDHCI_XENON
 	bool "SDHCI support for the Xenon SDHCI controller"
 	depends on MMC_SDHCI && DM_MMC && OF_CONTROL