Hi,
I was able to compile TF-A for rk3328 platform using the same command and specifying the CROSS_COMPILE as aarch64-linux-gnu-
I use the publicly available toolchain https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-a/downloads .In this case, I specifically used the 8.3 x86_64 Linux hosted cross compiler in my Ubuntu 18.04 (Virtual Box image ).
If I am not wrong, you dont have to use a cross compiler. However, I dont have access to a native Arm machine to test your build command. What compiler did you use?