build: support `make lint-c` with clang-tidy

build: support `make lint-c` with clang-tidy

This supports linting of C code using clang-tidy to fix common
security and code quality issues early in the development workflow.
The benefit is that less time has to be spent in code reviews to
point out obvious problems, and ideally when the outstanding issues
are fixed, clang-tidy (and clang-format) can also be used to to
automatically fix basic problems and enforce common code style,
similarly to `go vet && go fmt` workflow.