armv8: layerscape: Add TFABOOT support

Adds TFABOOT support config option and add generic code to enable
execution from DDR.

Signed-off-by: York Sun <york.sun@nxp.com>
Signed-off-by: Rajesh Bhagat <rajesh.bhagat@nxp.com>
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
index f2111fa..9092757 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
+++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
@@ -514,3 +514,10 @@
 	help
 	  For some SoC(such as LS1043A and LS1046A), USB and QE-HDLC multiplex use
 	  pins, select it when the pins are assigned to USB.
+
+config TFABOOT
+       bool "Support for booting from TFA"
+       default n
+       help
+         Enabling this will make a U-Boot binary that is capable of being
+         booted via TFA.