Pin 9, the RST pin on the cp2102 is the reset input to the chip.
This is more than likely what is is hooked to the header pin labeled RST.
To be sure you could verify it against the datasheet. https://www.silabs.com/Support%20Documents/TechnicalDocs/cp2102.pdf
See if the RST header pin is wired to pin 9 (RST) of the chip.
See page 7 of the chip spec to see the pinouts for the chip.
It is unfortunate that the designers of so many of these cp2102 boards have done this
as there is no real need to put this input signal on the header.
Perhaps they were dyslexic and thought they were hooking up the RTS signal
which would have been much better or perhaps they simply don't understand
what this signal is used for.
Other cp2102 boards like this:http://www.ebay.com/itm/USB-2-0-to-UART-TTL-6PIN-Module-Serial-Converter-CP2102-NEW-/180925940394?pt=US_Floppy_Zip_Jaz_Drives&hash=item2a2006c2aa
provide breakout for the control lines and you can re-wire things to use RTS or DTR.
I have several of these cp2102 boards and they will work with auto-reset if
you re-wire it to use DTR or RTS.
(I recommend using RTS as it offers some benefits over DTR).
For your board, if the header pin is the cp2102 RST input signal (which it probably is)
I'd recommend not wiring it up to anything as auto-reset to the AVR will never work and
there is no need to reset the cp2102, including when the arduino is reset.