remove the cmake option and compile cuda part as default

remove the USE_GPU option and definition in cmake, compile the cuda part in FastCaloSim-GPU if cuda is found. There will be some warning that it can not find some functions, i.e. LoadHistFuncsGpu, when loading the parameterization file, it should be fixed when we produce a new parameterization file with the cuda code included.

Ping @akraszna , @jchapman , @tlari , @mfauccig and @cyoung .