build: replace auto-discovered package lists with explicit definitions

[rucoder]

Description

NOTE: PR depends on alpine 3.22 update and must be rebased and retested when it is merged

We build some packages that are not part of architecture or platform e.g. u-boot, imx-bsp, etc make no sense for x86

Replace the fragile find pkg | grep -Ev ... auto-discovery of packages with explicit package lists split by category:

• COMMON_PKGS — packages built for every arch/hv/platform combination- ARCH_PKGS_* — architecture-specific (e.g. u-boot for arm64/riscv64)
• HV_PKGS_* — hypervisor-specific (e.g. kube for HV=k)
• PLATFORM_PKGS_* — platform-specific (e.g. nvidia, bsp-imx, optee-os)

This is done in two commits:

1. Fix get-deps tool to accept an explicit package list as positional arguments instead of unconditionally scanning all of pkg/. The Makefile now passes $(PKGS) to get-deps, and the pkg/kernel no-op workaround
   is removed.

2. Replace auto-discovery with explicit lists defined in the new mk/packages.mk. The final PKGS is assembled as: pkg/alpine $(COMMON_PKGS) $(ARCH_PKGS_$(ZARCH)) $(HV_PKGS_$(HV)) $(PLATFORM_PKGS_$(PLATFORM)). Moves kernel-version.mk into mk/ directory. Eliminates the hardcoded PKGS_riscv64 override that existed only to work around get-deps.

How to test and validate this PR

1. Run make pkgs for the default build (amd64/kvm/generic) and verify it builds the same set of packages as before.
2. Run make HV=k pkgs and verify pkg/kube and pkg/external-boot-image are included.
3. Run make PLATFORM=nvidia-jp5 ZARCH=arm64 pkgs and verify pkg/nvidia is included.
4. Verify pkg-deps.mk is generated correctly with make pkg-deps.mk — it should only contain rules for packages in PKGS.

Changelog notes

No user-facing changes.

PR Backports

• 16.0-stable: No, build-only refactoring.
• 14.5-stable: No, build-only refactoring.
• 13.4-stable: No, build-only refactoring.

Checklist

• I've provided a proper description

• I've added the proper documentation

• I've tested my PR on amd64 device

• I've tested my PR on arm64 device

• I've written the test verification instructions

• I've set the proper labels to this PR

• I've checked the boxes above, or I've provided a good reason why I didn't
  check them.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 28.34%. Comparing base (2281599) to head (ba4408e).
⚠️ Report is 445 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5751      +/-   ##
==========================================
+ Coverage   19.52%   28.34%   +8.81%     
==========================================
  Files          19       18       -1     
  Lines        3021     2417     -604     
==========================================
+ Hits          590      685      +95     
+ Misses       2310     1588     -722     
- Partials      121      144      +23     

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[andrewd-zededa]

@rucoder From a quick review the hv=k pkg list looks correct

[rucoder]

@rucoder From a quick review the hv=k pkg list looks correct

thank you @andrewd-zededa

[rene]

Full build for riscv64 must be supported first.