mmc: sdhci: Write to HOST_CONTROL2 register for HS400 speed mode

Enable HS400 speed mode by writing to HOST_CONTROL2 register.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Link: https://lore.kernel.org/r/20210405144428.12159-1-a-govindraju@ti.com
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index d9ab6a0..eea4701 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -507,6 +507,9 @@
 	case MMC_HS_200:
 		reg |= SDHCI_CTRL_UHS_SDR104;
 		break;
+	case MMC_HS_400:
+		reg |= SDHCI_CTRL_HS400;
+		break;
 	default:
 		reg |= SDHCI_CTRL_UHS_SDR12;
 	}