jerry: Enable LTO to save space
jerry: Enable LTO to save space

We're outta space on jerry.  Builders are failing.  It seems like we
can magically save space like CL:1663540 by turning on LTO.  Let's do
it!

Before on my local build:
  *** 28 bytes in flash and 5380 bytes in RAM still available on jerry RO ****
  *** 4476 bytes in flash and 5380 bytes in RAM still available on jerry RW ****

After on my local build:
  *** 3168 bytes in flash and 5448 bytes in RAM still available on jerry RO ****
  *** 7616 bytes in flash and 5448 bytes in RAM still available on jerry RW ****

BRANCH=None
BUG=chromium:1011621
TEST=See above

Change-Id: I2de0e6474a6d561fa4c44cc12d904a7c6339712f
Signed-off-by: Douglas Anderson <49983c4a76b998672954ed5edf4a62db4a336502@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1846231
Reviewed-by: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>
Reviewed-by: Bernie Thompson <88a16a105b67ec86732da208bff06a7d4d211801@chromium.org>

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