Cleanup ozone platform

Rename the platform to make it clear it is not just for eglfs. Fixes
formating, and also removes parts unnecessary for us that original ozone
platforms doesn't use anymore either.

Change-Id: I04e5792e2ced2580ae0cbfe208b4e594af60a09a
Reviewed-by: Michal Klocek <michal.klocek@qt.io>