Warning: No Clocks Defined in Design

I didn't yet think about a correct solution for your problem. But the present usage of lpm_shiftreg is obviously the reason, why the logic is completely removed by the compiler. I suggest, that you read the respective MegaFunction manual thoroughly. In a short, lpm_shiftreg is working like this: It's either loading the parallel input to the register, if load is asserted or shifting in serial data from shiftin. Cause both inputs are unconnected, it's doing nothing.