dw3000: temporarily disable -Wmissing-prototypes
This flag was recently enabled upstream in commit 0fcb70851fbf
("Makefile.extrawarn: turn on missing-prototypes globally"), which
triggers several errors in this repo. Disable the flag temporarily
until the individual issues get fixed.
Bug: 424610699
Change-Id: I1eaa07b3169a6161634251c6048e17114af13d2a
Signed-off-by: Carlos Llamas <[email protected]>