watchdog: Migrate OMAP_WATCHDOG to Kconfig

Move this entry to Kconfig.  As it is a hardware watchdog, select
HW_WATCHDOG.  While we could default to enabling this for all platforms,
it is currently only enabled by default on AM33XX, so keep that logic
today.

Cc: Roger Meier <r.meier@siemens.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bdaf5d4..22a7c4f 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -12,6 +12,14 @@
 	  This provides basic infrastructure to support BCM2835/2836 watchdog
 	  hardware, with a max timeout of ~15secs.
 
+config OMAP_WATCHDOG
+	bool "TI OMAP watchdog driver"
+	depends on ARCH_OMAP2PLUS
+	select HW_WATCHDOG
+	default y if AM33XX
+	help
+	  Say Y here to enable the OMAP3+ watchdog driver.
+	
 config ULP_WATCHDOG
 	bool "i.MX7ULP watchdog"
 	help