FROMLIST: kbuild: add ld-name macro

GNU gold may require different flags than GNU ld. Add a macro for
detecting the linker.

Bug: 62093296
Bug: 67506682
Change-Id: I777f14bf4fd902de1f8dc73d7ecc3c0403eae5f5
(am from https://patchwork.kernel.org/patch/10085775/

)
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>