Use soong_ui directly, instead of make

This will use ckati instead of make for dumping variables, for
consistent makefile parsing. It may also sandbox executions, etc.

Also skip the legacy make wrapper to build, and use soong_ui instead.
The command line arguments are equivalent, but -j is no longer
necessary, we'll default to a sane value.

Test: bit -b framework
Change-Id: Idc2c9d1abe84b6b783b8702925de5493d47a4509
diff --git a/tools/bit/make.h b/tools/bit/make.h
index bb83c6e..1c9504d 100644
--- a/tools/bit/make.h
+++ b/tools/bit/make.h
@@ -31,7 +31,7 @@
     vector<string> installed;
 };
 
-string get_build_var(const string& buildTop, const string& name, bool quiet);
+string get_build_var(const string& name, bool quiet);
 
 /**
  * Poke around in the out directory and try to find a device name that matches