added device implementation of CSR->ELL conversion based on Steven Dalton's code
added device implementation of CSR->ELL conversion based on Steven Dalton's code

tectronics/cusp-library,baiyunping333/cusp-library,tectronics/cusp-library,vkirangoud/cusp-library,vkirangoud/cusp-library,vkirangoud/cusp-library,tectronics/cusp-library,baiyunping333/cusp-library,tectronics/cusp-library,gshashidhar125/cusp-library,gshashidhar125/cusp-library,gshashidhar125/cusp-library,baiyunping333/cusp-library,vkirangoud/cusp-library,victordion/cusp-library,victordion/cusp-library,baiyunping333/cusp-library,gshashidhar125/cusp-library,victordion/cusp-library,victordion/cusp-library