[HIPIFY] Introduce CUDA installation path option '-cuda-path'

Repeats clang's '--cuda-path' option.

[Reason]
In case of absence of any other clang's options setting '-cuda-path' allows not to specify separator '--' before clang's '--cuda-path'.

+ Tests and scripts are updated accordingly.

tests/hipify-clang/unit_tests/samples/vec_add.cu

@@ -1,4 +1,4 @@
-// RUN: %run_test hipify "%s" "%t" %cuda_args
+// RUN: %run_test hipify "%s" "%t" %hipify_args %clang_args
 
 // Kernel definition
 __global__ void  vecAdd(float* A, float* B, float* C)