building wifi ac driver/module for BBB issue

I use Beagle Bone Black (BBB) and Arch few days:

Linux BBB 5.2.10-2-ARCH #1 PREEMPT Tue Aug 27 13:54:27 UTC 2019 armv7l GNU/Linux


I would like to build driver/module for Realtek RLT8821CU WIFI AC dongle.

BBB has the same architecture as RPI armv7l/armhf so I thought I could use driver for RPI.
I found and adjusted for RPI. I’ve build it in the Rasbian environment (kernel 4.19.66-v7+) and works OK for my RPI2.
I have applied the same adjustments (marks green):
to BBB but unfortunately during building I receive:

gcc: error: -mfloat-abi=soft and -mfloat-abi=hard may not be used together

This is strange because in the makefile I have only:

EXTRA_CFLAGS += -mfloat-abi=hard

see the line 1180 of Makefile:
(which worked fine for RPI).
What should I adjust in the Makefile (or somewhere else) to disable -mfloat-abi=soft?