updated gpu module docs

doc/gpu.tex

@@ -8,12 +8,18 @@
 Returns true if current GPU has native double support, false otherwise.
 
 \cvdefCpp{bool hasNativeDoubleSupport(int device);}
+\begin{description}
+\cvarg{device}{GPU identity.}
+\end{description}
 
 
 \cvCppFunc{gpu::hasAtomicsSupport}
 Returns true if current GPU has atomics support, false otherwise.
 
 \cvdefCpp{bool hasAtomicsSupport(int device);}
+\begin{description}
+\cvarg{device}{GPU identity.}
+\end{description}
 
 
 \section{Data Structures}