sdpu_build_partial_attrib_entry() function

* Function sdpu_build_partial_attrib_entry * Description This function fills a buffer with partial attribute. It is * assumed that the maximum size of any attribute is 256 bytes. * p_out: output buffer * p_attr: attribute to be copied partially into p_out * rem_len: num bytes to copy into p_out * offset: current start offset within the attr that needs to be copied * Returns Pointer to next byte in the output buffer. * offset is also updated