nautilus: Shrink accelerometer FIFO to 512 entries
nautilus: Shrink accelerometer FIFO to 512 entries

It appears that the shared memory buffer on Nautilus starts at
200c7720 D __shared_mem_buf

That's 29.78 kb into the RAM. Software sync needs 1kb, so we should
be fine, expect that the last 2kb of RAM are supposed to be reserved
for the "booter" (NPCX_BTRAM_SIZE).

We shrink the accelerometer FIFO to 512 entries, freeing up 4kb of
RAM, and increase the UART TX buffer to 4kb, to make use of 3kb of
that freed up space:
200c7320 D __shared_mem_buf

That's 28.78 kb into the RAM.

BRANCH=poppy
BUG=chromium:739771
TEST=make BOARD=nautilus -j, check that shared_mem_buf offset is
     < 29 kb.

Change-Id: I361a439b847d31d3415f2ee66229bd32f8816e2d
Signed-off-by: Nicolas Boichat <f3daba1cdc403799935674d3cd4b0e5bd1804232@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1002712
Commit-Ready: ChromeOS CL Exonerator Bot <fa429e5907f00867f797423aea74327bb02c91b6@appspot.gserviceaccount.com>
Reviewed-by: Philip Chen <3ee404f9ef892bc3fda6e6a76e65843b5fa44db2@chromium.org>
Reviewed-by: Gwendal Grignou <190c5a5edfcf62e0246559bf31fa7548674de3ad@google.com>
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