CRISv32: Avoid warning of unused variable

Avoids the warning about:
warning: 'bite_in_progress' defined but not used [-Wunused-variable]

Variable is only used if the Kconfig CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
is set.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>