samus_pd: Enable Link-Time Optimizations.
samus_pd: Enable Link-Time Optimizations.

BUG=None
BRANCH=None
TEST=`make -j BOARD=samus` succeeds.
TEST=samus_pd is able to boot up and negotiate correctly with zinger.

Change-Id: I422be2772df3436bb398ffd3e58096039efcbebe
Signed-off-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@google.com>
Reviewed-on: https://chromium-review.googlesource.com/998828
Commit-Ready: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Tested-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec