Tegra: Passing EKS size as boot arg to trusty

* EKS blob size was not passed by as a boot parameter
  earlier. Its being passed now
* If EKS value sent by bootloader is non-zero
  update the boot parameter from default value to the argument
  passed by bootloader

Change-Id: I65a3091bd2c1c908cc9e81c0aab6489cab02c098
Signed-off-by: Akshay Sharan <asharan@nvidia.com>

plat/nvidia/tegra/common/tegra_bl31_setup.c

@@ -251,6 +251,11 @@ void plat_trusty_set_boot_args(aapcs64_params_t *args)
 	args->arg0 = bl32_mem_size;
 	args->arg1 = bl32_boot_params;
 	args->arg2 = TRUSTY_PARAMS_LEN_BYTES;
+
+	/* update EKS size */
+	if (args->arg4 != 0U) {
+		args->arg2 = args->arg4;
+	}
 }
 #endif