add std modifier

src/include/migraphx/pad_calc.hpp

@@ -6,7 +6,7 @@
 namespace migraphx {
 inline namespace MIGRAPHX_INLINE_NS {
 
-inline size_t calculate_padding(size_t weight_dim, size_t dilation)
+inline std::size_t calculate_padding(std::size_t weight_dim, std::size_t dilation)
 {
     return (dilation * (weight_dim - 1)) / 2;
 }