Mark more fields in BaseLinkerProperties as arch variant

Bug: http://b/189438896

This allows setting a different version script for vendor and
platform variants.

Test: The following blueprint snippet builds:
      target: { android_arm64: {
        target: vendor: {
            version_script: "..." } } }
Change-Id: I47e7afeaee3c9124f4231bf0eece7b6844b5313d