watchdog: Remove BCM63XX_WDT

Now that we can utilize the BCM7038_WDT driver, remove that one which
was not converted to the watchdog APIs. There are a couple of notable
differences with how the bcm7038_wdt driver proceeds:

- bcm63xx_wdt would register with the ad-hoc BCM63xx hardware timer API,
  but this would only be used in order to catch the interrupt *before* a
  SoC reset and make the kernel "die"

- bcm6xx_wdt would register a software timer and kick it every second in
  order to pet the watchdog, thus offering a two step watchdog process.
  This is not something that is brought over to the bcm7038_wdt as it is
  deemed unnecessary. If user-space cannot pet the watchdog, but a
  kernel timer can, the system is still in a bad shape anyway.

bcm7038_wdt is simpler in its behavior and behaves as a standard
watchdog driver and is not making use of any specific platform APIs,
therefore making it more maintainable and extensible.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20211112224636.395101-8-f.fainelli@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/Kconfig

@@ -1697,16 +1697,6 @@ config OCTEON_WDT
 	  from the first interrupt, it is then only poked when the
 	  device is written.
 
-config BCM63XX_WDT
-	tristate "Broadcom BCM63xx hardware watchdog"
-	depends on BCM63XX
-	help
-	  Watchdog driver for the built in watchdog hardware in Broadcom
-	  BCM63xx SoC.
-
-	  To compile this driver as a loadable module, choose M here.
-	  The module will be called bcm63xx_wdt.
-
 config BCM2835_WDT
 	tristate "Broadcom BCM2835 hardware watchdog"
 	depends on ARCH_BCM2835 || (OF && COMPILE_TEST)

drivers/watchdog/Makefile

@@ -153,7 +153,6 @@ obj-$(CONFIG_XILINX_WATCHDOG) += of_xilinx_wdt.o
 # MIPS Architecture
 obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o
 obj-$(CONFIG_BCM47XX_WDT) += bcm47xx_wdt.o
-obj-$(CONFIG_BCM63XX_WDT) += bcm63xx_wdt.o
 obj-$(CONFIG_RC32434_WDT) += rc32434_wdt.o
 obj-$(CONFIG_INDYDOG) += indydog.o
 obj-$(CONFIG_JZ4740_WDT) += jz4740_wdt.o