configs: am43xx_evm: Avoid relocation onto firewall at the end of DRAM

On secure devices the initial secure software may install a firewall at
the end of DRAM, define protected RAM to avoid space.

Signed-off-by: Andrew F. Davis <afd@ti.com>

include/configs/am43xx_evm.h

@@ -326,4 +326,9 @@
 #define NANDBOOT
 #endif /* CONFIG_NAND */
 
+#if defined(CONFIG_TI_SECURE_DEVICE)
+/* Avoid relocating onto firewalled area at end of DRAM */
+#define CONFIG_PRAM (64 * 1024)
+#endif /* CONFIG_TI_SECURE_DEVICE */
+
 #endif	/* __CONFIG_AM43XX_EVM_H */