Use ccCmd to generate clang-tidy dependent file

* After this change, make libtinyxml2-tidy should generate
  correct out/.../libtinyxml2.tidy.d file.
  Touching one of the dependent files, e.g., tinyxml2.h,
  should invoke clang-tidy but not to recompile tinyxml2.o.
* Note that linking libraries still depend on .tidy targets,
  so make libtinyxml2 will call clang-tidy, regnerate
  tinyxml2.tidy.d, tinyxml2.tidy, tinyxml2.o.d, tinyxml2.o.
* A clang-tidy rule uses the same $cFlags for both clang and clang-tidy.
  To share it and avoid over long command lines, we use modern shell
  array variables and cannot use old bourne shell.

Bug: 199169329
Test: WITH_TIDY=1 make
Test: WITH_TIDY=1 make libtinyxml2-tidy | grep tinyxml2
Test: touch external/tinyxml2/tinyxml2.h; make libtinyxml2-tidy | grep tinyxml2
Change-Id: I6175add58d7313ee50c9308b78c9290a60770052