watchdog: geode: restore hard CS5535_MFGPT dependency

Wtihout CONFIG_CS5535_MFGPT, the driver does not link right:

drivers/watchdog/built-in.o: In function `geodewdt_probe':
geodewdt.c:(.init.text+0xca3): undefined reference to `cs5535_mfgpt_alloc_timer'
geodewdt.c:(.init.text+0xcd4): undefined reference to `cs5535_mfgpt_write'
geodewdt.c:(.init.text+0xcef): undefined reference to `cs5535_mfgpt_toggle_event'

This adds back the dependency on this base driver.

Fixes: da2a68b ("watchdog: Enable COMPILE_TEST where possible")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/watchdog/Kconfig

@@ -851,7 +851,7 @@ config SP5100_TCO
 
 config GEODE_WDT
 	tristate "AMD Geode CS5535/CS5536 Watchdog"
-	depends on CS5535_MFGPT || (X86 && COMPILE_TEST)
+	depends on CS5535_MFGPT
 	help
 	  This driver enables a watchdog capability built into the
 	  CS5535/CS5536 companion chips for the AMD Geode GX and LX