Watchdog support for ODROID C2

[Vincent DEFERT <vincent.defert%posteo.net@localhost>]

Hi!

The Meson GX watchdog also works on Meson GXBB, so the only modification 
required is to add the corresponding "compatible" line in 
sys/arch/arm/amlogic/mesongx_wdt.c:

static const struct device_compatible_entry compat_data[] = {
    { .compat = "amlogic,meson-gx-wdt" },
    { .compat = "amlogic,meson-gxbb-wdt" }, // <= ADD THIS LINE AND 
REBUILD KERNEL
    DEVICE_COMPAT_EOL
};

When the watchdog triggers, it performs a hardware reset, so the next 
boot takes a long time because file systems were not cleanly unmounted.
That said, if a watchdog triggers, there's probably worse than that to 
sort out. :)

Vincent