watchdog: Add wd_keepalive package

watchdog: Add wd_keepalive package

This is a simplified version of the watchdog daemon. It only opens
/dev/watchdog, and keeps writing to it often enough to keep the kernel
from resetting, at least once per minute. Each write delays the reboot
time another minute. After a minute of inactivity the watchdog hardware
will cause a reset. In the case of the software watchdog the ability to
reboot will depend on the state of the machines and interrupts.

Installs wd_keepalive binary and enable initscript.

(From OE-Core rev: b76af8a0982c3c7473bd6ba067d1c8030d4d2f26)

Signed-off-by: Fabio Berton <fabio.berton@ossystems.com.br>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>