[feature] Collect counters from /proc/interrupts

[Tungstwenty]

AFAIK this is a standard interface present in all kernels, and the counters might be marginally useful to help understand where do wakeups come from, at the hardware level. The device names will change between different phone models (hence only marginally useful, perhaps), but it might help in a scenario such as:

• Let the device turn off the screen
• Wake it up a while later
• Check the "since screen off" reference
• Assume the "time freeze" feature is already implemented
• Analyze executed apps, CPU time, wakelocks, interrupts, and it might show some insights of the possible reasons for non-deep sleep time even when there's nothing very relevant on the app side (wakelocks, alarms, etc.)

[asksven]

IMHO dmesg and PM events are a better approach to this but I will have a look into it