[ALL][i.MX6QDL][A62] Add GPIO watchdog driver
This patch adds a driver for gpio-based WDTs that use two gpios: enable and trigger. This driver is based on the linux GPIO-controlled Watchdog driver. It was necessary for enabling the watchdog on A62, since on reboot it was noticed its absence prevented the correct reinitialization of lvds. There exists another driver that could be used for similar hardware, called with the compatible name "seco,apx-wdog". That one initializes the watchdog early in the boot process, and is used for more complex cases.