graphics/mesa-devel: unbreak build on aarch64 around 9557360d5a11

FAILED: [code=1] src/gallium/targets/rusticl/libRusticlOpenCL.so.1.0.0
ld: error: ld-temp.o <inline asm>:3:1: symbol 'loop64' is already defined
loop64:
^

ld: error: ld-temp.o <inline asm>:3:1: symbol 'loop64' is already defined
loop64:
^

ld: error: ld-temp.o <inline asm>:3:1: symbol 'loop64' is already defined
loop64:
^

ld: error: ld-temp.o <inline asm>:3:1: symbol 'loop64' is already defined
loop64:
^

c++: error: linker command failed with exit code 1 (use -v to see invocation)

Reported by: pkg-fallout

(cherry picked from commit 8728aea7c8875bf54eececbc2f5468bb19ed5bc3)