Define PATH_TO_CLANG_TIDY_SHELL for build/make rules.

* PATH_TO_CLANG_TIDY_SHELL is ${config.ClangTidyShellPath},
  wich is "build/soong/scripts/clang-tidy.sh"

Bug: 110538415
Test: build with WITH_TIDY=1
Change-Id: I27d7be095c998583fa9ad4d705aa1332bd018140
diff --git a/cc/makevars.go b/cc/makevars.go
index c3ff4ce..5b9ac1d 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -75,6 +75,7 @@
 	ctx.Strict("LLVM_OBJCOPY", "${config.ClangBin}/llvm-objcopy")
 	ctx.Strict("LLVM_STRIP", "${config.ClangBin}/llvm-strip")
 	ctx.Strict("PATH_TO_CLANG_TIDY", "${config.ClangBin}/clang-tidy")
+	ctx.Strict("PATH_TO_CLANG_TIDY_SHELL", "${config.ClangTidyShellPath}")
 	ctx.StrictSorted("CLANG_CONFIG_UNKNOWN_CFLAGS", strings.Join(config.ClangUnknownCflags, " "))
 
 	ctx.Strict("RS_LLVM_PREBUILTS_VERSION", "${config.RSClangVersion}")