fix(ethos-n): update build flag in tf config

The tf build configuration for the Arm(R) Ethos(TM)-N NPU driver is
using an out of date build flag and has been updated with the correct
flag.

Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>
Change-Id: Ia704c897985fb988ccadfaba7f49fa755d5a5c5c
1 file changed