ls1021atwr: caam: Enable Uboot validaion in SPL.

caam driver model enabled in spl for secure boot.
fsl_rsa_mod_exp driver enabled in spl for validating uboot image.

Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
diff --git a/board/freescale/common/fsl_validate.c b/board/freescale/common/fsl_validate.c
index f56e4e8..7a23d8f 100644
--- a/board/freescale/common/fsl_validate.c
+++ b/board/freescale/common/fsl_validate.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright 2015 Freescale Semiconductor, Inc.
- * Copyright 2021 NXP
+ * Copyright 2021-2022 NXP
  */
 
 #include <common.h>
@@ -19,6 +19,7 @@
 #ifdef CONFIG_ARCH_LS1021A
 #include <asm/arch/immap_ls102xa.h>
 #endif
+#include <dm/lists.h>
 
 #define SHA256_BITS	256
 #define SHA256_BYTES	(256/8)
@@ -807,6 +808,13 @@
 	prop.num_bits = key_len * 8;
 	prop.exp_len = key_len;
 
+#if defined(CONFIG_SPL_BUILD)
+	ret = device_bind_driver(NULL, "fsl_rsa_mod_exp", "fsl_rsa_mod_exp", NULL);
+	if (ret) {
+		printf("Couldn't bind fsl_rsa_mod_exp driver (%d)\n", ret);
+		return -EINVAL;
+	}
+#endif
 	ret = uclass_get_device(UCLASS_MOD_EXP, 0, &mod_exp_dev);
 	if (ret) {
 		printf("RSA: Can't find Modular Exp implementation\n");