zephyr: Move watchdog initialization earlier
zephyr: Move watchdog initialization earlier

On CrosEC the watchdog is initialized just after printing banner.
Without this change, hangup in eg. vboot hash calculation can
result in EC being unresponsive.

BUG=none
BRANCH=none
TEST=Add infinite loop in hash calculation function (efs2.c).
     Without this change, EC will be unresponsive.
     With it, watchdog will reboot the EC.

Change-Id: I68c33bf79ad9645da55c1782662c19d9cb7cc58d
Signed-off-by: Michał Barnaś <77666125932addc6fc525b281b518fd8fd2203d8@semihalf.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2897240
Reviewed-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>
Commit-Queue: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>

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