main/postmarketos-base: stop the power key from shutting down devices
Pressing power button should not power off a device. Although it is expected on desktops and laptops, it isn't expected on phones and tablets. Instead it should just turn off the screen or go into a deep sleep, but that isn't handled by elogind. So let elogind just ignore the button altogether.
Also re-order the dependencies alphabetically while we're touching the package anyway.
We're doing this in postmarketos-base rather than the UI packages that depend on elogind since we want this for all devices.