chrome-sdk: set correct gold path.
chrome-sdk: set correct gold path.

The previous behavior of setting -fuse-ld=ld.gold didn't work because
the Chrome build always adds a -B path pointing to the 64 bit gold
linker, which overrides the -fuse-ld flag.

So we are reverting to what the Chrome ebuild does - append an
overriding -B path to the right gold linker.

The right long term fix is tracked in crbug.com/177353.

TEST=Verified x86-alex (32 bit) and daisy build.
BUG=None

Change-Id: I941ab871d6a82f5ac7d42ca915b16507f293a2fe
Reviewed-on: https://gerrit.chromium.org/gerrit/43536
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Commit-Queue: Ryan Cui <5ce1592d53754a87a44fc2eb7b63d5f77cf50fdb@chromium.org>
Tested-by: Ryan Cui <5ce1592d53754a87a44fc2eb7b63d5f77cf50fdb@chromium.org>
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>

bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,chadversary/chromiumos.chromite,zhang0137/chromite,zhang0137/chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite