gpio/cs5535: Show explicit dependency between gpio_cs5535 and mfd_cs5535

cs5535-gpio.c has been split into two, with various setup moved
into cs5535-mfd.c.  Given that cs5535-gpio will not load without
the -mfd part, lets make that dependency explicit in Kconfig
Signed-off-by: NEd Wildgoose <kernel@wildgooses.com>
Acked-by: NAndres Salomon <dilinger@queued.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/gpio/Kconfig

@@ -303,7 +303,7 @@ comment "PCI GPIO expanders:"
 
 config GPIO_CS5535
 	tristate "AMD CS5535/CS5536 GPIO support"
-	depends on PCI && X86 && !CS5535_GPIO
+	depends on PCI && X86 && !CS5535_GPIO && MFD_CS5535
 	help
 	  The AMD CS5535 and CS5536 southbridges support 28 GPIO pins that
 	  can be used for quite a number of things.  The CS5535/6 is found on