Kconfig: Enable building of u-boot.itb on Rockchip platform

For all the Rockchip SoCs with SPL_LOAD_FIT enable, we need to build
u-boot.itb with U-Boot proper and ATF/OPTEE.

All the Rockchip boards with SPL_LOAD_FIT now supports FIT generator to
get ATF/OPTEE binary path from environment and pass the build even if no
ATF/OPTEE binary exist, so we can enable this feature for the rockchip
platform.
Signed-off-by: NKever Yang <kever.yang@rock-chips.com>

Kconfig

@@ -252,7 +252,7 @@ config BUILD_TARGET
 	default "u-boot-with-spl.sfp" if TARGET_SOCFPGA_GEN5
 	default "u-boot-spl.kwb" if ARCH_MVEBU && SPL
 	default "u-boot-elf.srec" if RCAR_GEN3
-	default "u-boot.itb" if SPL_LOAD_FIT && (ROCKCHIP_RK3399 || \
+	default "u-boot.itb" if SPL_LOAD_FIT && (ARCH_ROCKCHIP || \
 				ARCH_SUNXI || RISCV)
 	default "u-boot.kwb" if KIRKWOOD
 	default "u-boot-with-spl.bin" if ARCH_AT91 && SPL_NAND_SUPPORT