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/am65x_evm_a53_defconfig b/configs/am65x_evm_a53_defconfig
index 500335f..3afa80f 100644
--- a/configs/am65x_evm_a53_defconfig
+++ b/configs/am65x_evm_a53_defconfig
@@ -73,6 +73,7 @@
 CONFIG_MTDIDS_DEFAULT="nor0=47040000.spi.0"
 CONFIG_MTDPARTS_DEFAULT="mtdparts=47040000.spi.0:512k(ospi.tiboot3),2m(ospi.tispl),4m(ospi.u-boot),128k(ospi.env),128k(ospi.env.backup),1m(ospi.sysfw),-@8m(ospi.rootfs)"
 CONFIG_CMD_UBI=y
+CONFIG_MMC_SPEED_MODE_SET=y
 # CONFIG_ISO_PARTITION is not set
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y