staging: fix olpc_dcon build errors

drivers/staging/olpc_dcon/olpc_dcon_xo_1_5.c: In function ‘dcon_wiggle_xo_1_5’:
drivers/staging/olpc_dcon/olpc_dcon_xo_1_5.c:155: error: implicit declaration of function ‘udelay’
drivers/built-in.o: In function `dcon_read_status_xo_1':
olpc_dcon_xo_1.c:(.text+0x13472e): undefined reference to `cs5535_gpio_set'

Signed-off-by: Sascha Silbe <sascha-pgp@silbe.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/olpc_dcon/Kconfig b/drivers/staging/olpc_dcon/Kconfig
index f1082f5..b053067 100644
--- a/drivers/staging/olpc_dcon/Kconfig
+++ b/drivers/staging/olpc_dcon/Kconfig
@@ -9,7 +9,7 @@
 
 config FB_OLPC_DCON_1
 	bool "OLPC XO-1 DCON support"
-	depends on FB_OLPC_DCON
+	depends on FB_OLPC_DCON && GPIO_CS5535
 	default y
 	---help---
 	  Enable support for the DCON in XO-1 model laptops.  The kernel