Improve NDK section in Makefile

This PR sets the "comp" variable simply to "clang",
which seems to be more consistent and allows a small simplification.

The PR also moves the section that sets "profile_make" and "profile_use" to after the NDK section,
which ensures that these variables are now set correctly for NDK/clang.

closes https://github.com/official-stockfish/Stockfish/pull/3121

No functional change