If the watchdog is enabled, set the timeout to 30 seconds before
decompress is started.
Mikrotik ipq40xx devices running with RouterBoot have the SoC watchdog
enabled and running with a timeout that does not allow time for the
kernel to decompress and manage the watchdog.
On ipq40xx RouterBoot TFTP boot the watchdog countdown is reset before:
Jumping to kernel
Signed-off-by: John Thomson <git@johnthomson.fastmail.com.au>
