Linux kernel compilation failure with CONFIG_EXTRA_FIRMWARE

I am trying to compile Linux kernel with extra firmware, but in compilation it is taking wrong path for firmware. I added following extra config in my build kernel.

 extraConfig = 
''
 EXTRA_FIRMWARE "ath10k/QCA6174/hw3.0/board-2.bin ath10k/QCA6174/hw3.0/firmware-6.bin ath10k/QCA988X/hw2.0/board.bin ath10k/QCA988X/hw2.0/firmware-4.bin ath10k/QCA988X/hw2.0/firmware-5.bin regulatory.db regulatory.db.p7s"
EXTRA_FIRMWARE_DIR "${pkgs.ath10k-firmware}/lib/firmware"
''

But I am getting following error:

make[4]: *** No rule to make target '../\/nix/store/8s8rj019pspkdq5a8d46snmsi13fgjwq-ath10k-firmware-riscv64-unknown-linux-gnu/lib/firmware\/\ath10k/QCA6174/hw3.0/board-2.bin', needed by 'drivers/base/firmware_loader/builtin/\ath10k/QCA6174/hw3.0/board-2.bin.gen.o'.  Stop.
make[4]: *** Waiting for unfinished jobs....

This is tying to pick the firmware from parent directory.