As @Phil9 has mentioned, if you need to reboot the AP everytime you have a power outage in the network(s), you have something fundamentally wrong which perhaps you may want to solve urgently.
It's also quite a question on how you will do this.
How are you going to deploy some kind of monitoring on this? Checking if the APs replying to ping, or using API to check if APs are offline in a timely fashion, etc?
Anyway, given it's a rare case that we move around APs, to build a database on where the APs are connected to your switch, a simple way is just to download the information on the Meraki dashboard (Network -> Wireless -> Access Points) and make sure you have the "Ethernet 1 LLDP" column checked and then download it as csv.
Of course, you will then have to work on the column as it will give you "[switch name]/[port id]" by leveraging it to contain switch serial, for example, and maybe other information that you need (switch IP address, etc)
When you need to reboot your APs via API you can use https://developer.cisco.com/meraki/api-v1/cycle-device-switch-ports/ based on the database that you have built.
Again, as mentioned previously, something is wrong if you have to do this everytime you have a power outage on the network.