npcx: Do not reload the OFMCLK when system-jump
npcx: Do not reload the OFMCLK when system-jump

When the OFMCLK is reloaded, it will be stopped until the clock
generation becomes stable. During this narrow window, any eSPI response
from EC will be abnormal. However, we needn't change the OFMCLK during
system-jump because it should be set only once when EC powers on.

BUG=b:145369656
BRANCH=none
TEST=Pass "make buildall"
TEST=The symptom no longer occurs for 3 hours stress test.

Change-Id: Idcc745f11119ba3781787b8b5e77ea620264e908
Signed-off-by: CHLin <84d2fca36f9d804bb7b1903655f14e4c722a99c4@nuvoton.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1994685
Tested-by: CH Lin <49997681dc186e71092740314bf6c6feeca6e227@nuvoton.com>
Reviewed-by: Tim Wawrzynczak <86444811eee8c2cb29e29a251d7a069e64ccc665@chromium.org>
Commit-Queue: CH Lin <49997681dc186e71092740314bf6c6feeca6e227@nuvoton.com>

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