it83xx/spi: drop static modifier
it83xx/spi: drop static modifier

spi_get_protocol_info is now declared in the spi.h, so we should
drop the modifier.

BRANCH=master
BUG=none
TEST=make buildall -j

Change-Id: I499f0a99f05d6881dd76ceb873b28d362b86068c
Signed-off-by: Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2235239
Commit-Queue: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@chromium.org>
Tested-by: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@chromium.org>
Reviewed-by: Tzung-Bi Shih <5e6f7578cd434ae5b4c9ffe5250f7a87a25045d7@chromium.org>

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