configs: am62ax_evm_a53_defconfig: Enable YMODEM support at A53 SPL

This is required for UART boot flow where u-boot.img needs to be
downloaded via YMODEM.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Bryan Brattlof <bb@ti.com>
diff --git a/configs/am62ax_evm_a53_defconfig b/configs/am62ax_evm_a53_defconfig
index 41fa6f3..76ec5ed 100644
--- a/configs/am62ax_evm_a53_defconfig
+++ b/configs/am62ax_evm_a53_defconfig
@@ -35,6 +35,7 @@
 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME="u-boot.img"
 CONFIG_SPL_DM_MAILBOX=y
 CONFIG_SPL_POWER_DOMAIN=y
+CONFIG_SPL_YMODEM_SUPPORT=y
 CONFIG_CMD_MMC=y
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y