The T0 protocol (selected in transport/pcsc.py) does not support extended APDU, so 255 bytes is the maximum number of bytes that can be transmitted at a time. We can divide large data into 255 byte chunks. The read_binary function already has code to read more than 255 bytes, so we can just adapt it to the update_binary function.
Change-Id: Icc240d5c8c04198640eb118565ea99f10ba27466