configs: am62ax_evm_a53_defconfig: Enable MMC_SPEED_MODE_SET

Enable MMC_SPEED_MODE_SET config option in defconfig to enable
changing MMC bus modes with mmc rescan for am62ax device.

Signed-off-by: Judith Mendez <jm@ti.com>
diff --git a/configs/am62ax_evm_a53_defconfig b/configs/am62ax_evm_a53_defconfig
index a070182..5e80c68 100644
--- a/configs/am62ax_evm_a53_defconfig
+++ b/configs/am62ax_evm_a53_defconfig
@@ -41,6 +41,7 @@
 CONFIG_SPL_POWER_DOMAIN=y
 CONFIG_SPL_YMODEM_SUPPORT=y
 CONFIG_CMD_MMC=y
+CONFIG_MMC_SPEED_MODE_SET=y
 CONFIG_CMD_REMOTEPROC=y
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y