arm64: zynqmp: Add support for u-boot.itb generation with ATF

Follow i.MX, Sunxi, RISC-V and Rockchip to generate u-boot.itb which
includes U-Boot proper, ATF and DTBs in FIT format. ZynqMP supports FIT for
quite a long time but with using out of tree solution. The patch is filling
this gap.

Tested on zcu102, zcu104 and zcu100/Ultra96.

zcu100/Ultra96 v2.2 ATF build by:
make DEBUG=0 ZYNQMP_CONSOLE=cadence1 RESET_TO_BL31=1 PLAT=zynqmp bl31

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/include/configs/xilinx_zynqmp.h b/include/configs/xilinx_zynqmp.h
index 9e08ed5..b094dce 100644
--- a/include/configs/xilinx_zynqmp.h
+++ b/include/configs/xilinx_zynqmp.h
@@ -242,7 +242,11 @@
 # define CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR	0 /* unused */
 # define CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS	0 /* unused */
 # define CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR	0 /* unused */
-# define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME	"u-boot.img"
+# if defined(CONFIG_SPL_LOAD_FIT)
+#  define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME	"u-boot.itb"
+# else
+#  define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME	"u-boot.img"
+# endif
 #endif
 
 #if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_DFU)