35.3.1 compile 8821cu failed

This is my change:

kernel/kernel-5.10/arch/arm64/configs/defconfig
@@ -3164,7 +3164,7 @@ CONFIG_DHD_SET_RANDOM_MAC_VAL=0x001A11
 # CONFIG_RTL8812AU is not set
 # CONFIG_RTL8814AU is not set
 # CONFIG_RTL8821AU is not set
-# CONFIG_RTL8821CU is not set
+CONFIG_RTL8821CU=m
 # CONFIG_RTL8822BU is not set
 CONFIG_RTL8822CE=m

But when I start building kernel, the error happended.
Here is the log:
build 8821cu failed.txt (9.9 KB)

The driver path is kernel/nvidia/drivers/net/wireless/realtek/rtl8821cu,
which provided by SDK in default.
Can any one help me solve it?

Can someone do me a favour to pick up this problem?