watchdog: sama5d4_wdt: addition of sam9x60 compatible watchdog

Add support for SAM9X60 WDT into sama5d4_wdt.
This means that this driver gets a flag inside the data struct
that represents the sam9x60 support.
This flag differentiates between the two hardware blocks, and is set
according to the compatible of the driver instantiation.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1574067012-18559-3-git-send-email-eugen.hristev@microchip.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>