Description of problem: yum list does not show any support for RTC devices for Fedora 18 ARM as was present in Fedora 17 ARM. Thus it appears if i2c based RTC clock device is installed on hardware (RTC ds1307 for example), such as Arduino or Raspberry Pi, Fedora 18 ARM has no method to leverage device. This is rather short sighted of the Fedora ARM team given the great popularity of such devices.
I'm not sure what you would expect 'yum list' to show for RTC devices. The I2C RTC device drivers are still built in the F18 arm kernels. However, Fedora doesn't officially support the Raspberry Pi as all the necessary source isn't upstream. The Pidora release does provide that support. Going forward (F20 and beyond), Fedora ARM will only support ARMv7 hardware anyway. Can you be more specific on what you are actually seeing?
armv5tel is actually end of life with Fedora 18, we actually dropped support for it in F-19. Pidora is a different project that supports the Raspberry Pi as a separate project and any issues with the RPi HW should be directed to the Pidora team and the details for for how to do that is on their site http://pidora.ca That being said the mainline Fedora kernel still builds the ds1307 RTC driver with i2c support as a driver on the mainline kernel (no idea about the Pidora kernel) so it would still be usable if you're using a ARMv7 platform that is supported on Fedora.