[PATCH v7] Add optimized Makefile support for SoCFPGA handoff

[Sune Brian]

> Add optimized Makefile support for SoCFPGA handoff
>
> - Introduce socfpga_g5_hanoff_prepare target in U-Boot
>   arch/arm/mach-socfpga/config.mk
> - Users can convert the handoff via make prepare.
> - Detects Altera/Intel SoCFPGA boards from .config
> - Combines vendor/board extraction into a single shell call
> - Checks for hps_isw_handoff folder and .hiof files
> - Uses ls -d instead of find for faster folder detection
> - Runs BSP generator script only if files exist
> - Non-blocking: continues if handoff folder or files are missing
> - HANDOFF_PATH user define allows overriding auto-detected folder
> - Minimizes subshells and other slow constructs for faster CI

Any trouble on this new compile flow?

Brian