ac: automake: rework sid_tables.h generation

Drop $(srcdir)/ prefix analogous to before the file (and rule) movement
and move it outside of the NEED_RADEON_LLVM conditional.

Otherwise the build may fail as below.

make[3]: *** No rule to make target 'common/sid_tables.h', needed by 'distdir'.  Stop.

Fixes: b838f642371 "ac/debug: Move sid_tables.h generation to common
code."
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
2 files changed