mmc: Add support for the no-mmc-hs400 prop

The linux commit f722e650d965 ("mmc: core: add support for disabling
HS400 mode via DT") added support for a no-mmc-hs400 prop.

Add support for the no-mmc-hs400 prop to disable HS400 host caps.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Dragan Simic <dsimic@manjaro.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/mmc-uclass.c b/drivers/mmc/mmc-uclass.c
index 22c64aa..24170c5 100644
--- a/drivers/mmc/mmc-uclass.c
+++ b/drivers/mmc/mmc-uclass.c
@@ -262,6 +262,9 @@
 		cfg->host_caps |= MMC_CAP(MMC_HS_400) | MMC_CAP(MMC_HS_200);
 	if (dev_read_bool(dev, "mmc-hs400-enhanced-strobe"))
 		cfg->host_caps |= MMC_CAP(MMC_HS_400_ES);
+	if (dev_read_bool(dev, "no-mmc-hs400"))
+		cfg->host_caps &= ~(MMC_CAP(MMC_HS_400) |
+				    MMC_CAP(MMC_HS_400_ES));
 
 	if (dev_read_bool(dev, "non-removable")) {
 		cfg->host_caps |= MMC_CAP_NONREMOVABLE;