Add = sign for the A380x ECAM font

### Aircraft Version

Development

### Description

The equal sign = added to the A380x font file.

### References (optional)

<img width="241" height="19" alt="Image" src="https://github.com/user-attachments/assets/dfa8e473-2a03-4c53-ac28-b7ee69888863" />

### Additional info (optional)

This is required before PR #10253 can be merged

### Discord Username (optional)

jonny_23