Update uptime to absolute time values

[chemelli74]

The problem

Uptime should use absolute time values and not relative time values.
This is the list of the letfovers:

Sensors:

• esphome
• fritzbox_netmonitor
• google_wifi
• guardian
• qna

Attributes:

• freebox (router.py)
• mikrotik (hub.py)
• wemo (switch.py)

[DAVe3283]

I was actually just about to post an issue that is the opposite of this. I prefer the ESPHome way of reporting the current uptime as an accumulating number of seconds. Makes the data much more friendly for things like InfluxDB and Grafana.

[chemelli74]

I was actually just about to post an issue that is the opposite of this. I prefer the ESPHome way of reporting the current uptime as an accumulating number of seconds. Makes the data much more friendly for things like InfluxDB and Grafana.

This is an architecture design and 99% of HA is already compliant.

Simone