As I did for Yosemite in "OS X Yosemite and smart card source code" I will document what I found.
The smart card related components are:
See "OS X El Capitan and smart cards status" for a general discussion of the changes in El Capitan.
General remark
Apple published the source code at the same time they published the 2nd minor version of El Capitan: 10.11.2. Maybe Apple wanted to fix the most serious bugs before publishing the source code. Or maybe they had not enough free time before today?SecurityTokend
The version did not changed from 55108 in Yosemite to 55108 in El Capitan.It is surprising to see a Tokend related component. CDSA (and then tokend) has been deprecated in 2011.
Maybe Apple forgot to remove this component?
SmartcardCCID
The version did not changed from 55008 in Yosemite to 55008 in El Capitan.The CCID driver has not changed between Yosemite and El Capitan. This is what I already found in "OS X El Capitan and smart cards status".
SmartCardServices
The version did not changed from 55111 in Yosemite to 55111 in El Capitan.SmartCardServices is the component providing pcsc-lite. For Yosemite Apple rewrote the complete PC/SC stack and replaced pcsc-lite by something else. So this component is not used in El Capitan.
Maybe Apple forgot to remove this component?
Conclusion
No change at all since Yosemite in the Open Source components related to smart card.The PC/SC layer changed. Apple fixed some bugs between Yosemite and El Capitan, see "OS X Yosemite and smart cards: known bugs". But Apple still does not provide the source code of this component.
Components not used any more in El Capitan are still provided in OS X 10.11 Source. It looks like Apple forgot to clean the list of the components used in El Capitan.