Fixed HIP compilation.

include/kernels_gpu.h

@@ -176,10 +176,10 @@ gpu_compute_rk4_weighted_sum(double *out, const double *in, const double *k1,
 void
 gpu_compute_leapfrog_update(double *next, const double *curr, const double *soe,
     const double *tmp, const double *ie, size_t num_dofs, double dt,
-    cudaStream_t stream = 0);
+    gpuStream_t stream = 0);
 
 void
 gpu_compute_leapfrog_update(double *next, const double *curr,
     const double *tmp, const double *im, size_t num_dofs, double dt,
-    cudaStream_t stream = 0);
+    gpuStream_t stream = 0);