[Tests] EAS RFC test crashes if used with rebooting and kernel update feature

Created by: derkling

Reported by: Morten Rasmussen

rfc.py:EAS test crashes if used on TC2 with rebooting feature if the kernel has been updated.

The 60s waiting time appears to be insufficient time for TC2 to reboot if a new kernel has to be loaded into flash by the bootloader.

Maybe have a more flexible approach poking the target ip-address every 5s to see if it is up and ssh login is possible instead of a fixed wait period?

TestEnv.reboot() is currently not useable on TC2 due to the short time-out.