[Feature Request]: EFI/GRUB boot support for AYN Odin 2

### Which feature would you like to have?

I am using an AYN Odin 2 and running both Armbian and Rocknix on the device.

Recently, Rocknix introduced a new ABL that enables Linux booting across multiple devices using an EFI/GRUB-based boot flow. However, this has created a compatibility issue with Armbian.

**Current situation**

- Armbian currently uses LinuxLoader-based boot
- Rocknix uses EFI/GRUB-based boot
- The ABL required for each system is not compatible with the other

As a result, switching between Armbian and Rocknix requires:

- Reflashing the ABL each time
- This is inconvenient and potentially dangerous, as it involves repeatedly modifying bootloader partitions

**Problem**

This prevents a clean dual-boot setup (Linux + Android), since:

- Each Linux system requires a different ABL
- There is no shared boot method between Armbian and Rocknix

**Proposed solution**

Implement support for EFI/GRUB boot in Armbian for the Odin 2, similar to Rocknix.

This would allow:
- Booting Armbian and Rocknix using the same ABL
- Switching systems simply by changing the SD card
- Avoiding repeated flashing of bootloader partitions

**Benefits**

- Safer (no repeated ABL flashing)
- Better user experience
- Standardized boot method across Linux distributions
- EFI/GRUB provides more flexibility and maintainability

**Additional context**

The goal is not multiboot between multiple Linux systems simultaneously, but rather:

- Reliable dual usage of different Linux systems (Armbian or Rocknix) alongside Android
- Without modifying bootloader partitions each time

### Funding

- [ ] [I am willing to cover expenses](https://www.armbian.com/contact/)