watchdog: bcm281xx: Watchdog Driver

This commit adds support for the watchdog timer used on the BCM281xx
family of SoCs.

Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --cc arch/arm/configs/bcm_defconfig
Simple merge

diff --cc drivers/watchdog/Kconfig
Simple merge

diff --cc drivers/watchdog/Makefile
Simple merge

diff --cc drivers/watchdog/bcm_kona_wdt.c
Simple merge