Fixes the following building error in Android:

In file included from external/mesa/src/amd/common/ac_llvm_helper.cpp:34:
In file included from external/mesa/src/amd/common/ac_llvm_build.h:30:
In file included from external/mesa/src/compiler/nir/nir.h:40:
In file included from external/mesa/src/compiler/nir_types.h:36:
external/mesa/src/compiler/glsl_types.h:37:10: fatal error: 'main/config.h' file not found
         ^~~~~~~~~~~~~~~
1 error generated.

Fixes: bd4c661a

 ("ac,ac/nir: use a better sync scope for shared atomics")
Signed-off-by: Mauro Rossi <issor.oruam@gmail.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>