Have you seen the Community Ocean Project? It might meet your needs.
If not, that shader looks like it would need some custom code anyway, so it would be quicker and easier to convert the code itself. Luckily, HLSL and GLSL are very similar. To convert between them you pretty much just need to replace a few type/function/variable names. Here’s a short guide. Give your HLSL shader a .usf extension. Put it in Epic Games/4.x/Engine/Shaders/ Open MaterialTemplate.usf in the same folder and add a line to include your shader file. Now, if you use a custom node in the material editor, you can call functions from your shader. In the code field put something like “return functionname(x);” no quotes. Make sure the custom node’s output type is the same as the function, and that it has the same number of inputs, with the same names, as the function.