Yet another great and needful tweak!!! Where you’ll get?? Of course Cydia !!!
GPower adds RestartSB, Reboot option to your power button. You won’t find it any icon for this, but when you press the power button, you’ll find extra sliders for RestartSB and Reboot along with power off.
This app is available for free in Cydia under BigBoss and Planet-iPhones Repo