configs: am6*_evm_a53_defconfig: Enable config to support mmc rescan

Enable MMC_SPEED_MODE_SET config option in defconfig to enable
mmc rescan for various Sitara devices.

Signed-off-by: Judith Mendez <jm@ti.com>
diff --git a/configs/am62x_evm_a53_defconfig b/configs/am62x_evm_a53_defconfig
index 4c1e4d7..a25f7b2 100644
--- a/configs/am62x_evm_a53_defconfig
+++ b/configs/am62x_evm_a53_defconfig
@@ -50,6 +50,7 @@
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x280000
 CONFIG_SPL_YMODEM_SUPPORT=y
 CONFIG_CMD_MMC=y
+CONFIG_MMC_SPEED_MODE_SET=y
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y
 CONFIG_MULTI_DTB_FIT=y