Since we have a CMake target, we can do scoped include directories.
Remove duplicate compile flags, and also add compile definitions which
enables PBRT to compile on Windows for Pascal-architecture cards.

Compared to commit a685e020, this also

* changes the dependency to be directly on the library rather than some
  of its object file;
* adds a missing dependency on several generated header files;
* avoids passing `/D _CRT_SECURE_NO_WARNINGS` to nvcc;
* removes compiler flags that are part of the regular CUDA flags.