2e: Set CPU variants to cortex-a53

Description

This MR resolves the linked issue

Issue(s)

• https://gitlab.e.foundation/e/devices/backlog/-/issues/135

Test environment

Generate a build with this MR

Test procedures

Flash and boot the generated build, ensure everything works as expected

Technical details

None available

Screenshots

None available

Checklist

• Self-review
• Test procedure explained
• Tested applied as an update