android: gallium/radeonsi: w16 build fix
Fixes the following building error:
FAILED: out/target/product/x86_64/obj/STATIC_LIBRARIES/libmesa_pipe_radeonsi_intermediates/si_shader_nir.o ... In file included from external/mesa/src/gallium/drivers/radeonsi/si_shader_nir.c:26: external/mesa/src/amd/common/ac_nir.h:29:10: fatal error: 'nir.h' file not found ^~~~~~~ 1 error generated.
Fixes: 1c702a82 ("ac: move ac_lower_indirect_derefs() outside of the LLVM dir")