gnu: Add value (=1) to the v8.1m arch define

Signed-off-by: Dávid Házi <david.hazi@arm.com>
Change-Id: Ib08dac239996dc13f9f057399b4b1c28e25698cd
(cherry picked from commit 16cd9931cdce86370a9c247aba22597d7dcd723e)
2 files changed