[S390] Kconfig: refine depends statements.

Refine some depends statements to limit their visibility to the
environments that are actually supported.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/message/fusion/Kconfig b/drivers/message/fusion/Kconfig
index 71037f9..c88cc75 100644
--- a/drivers/message/fusion/Kconfig
+++ b/drivers/message/fusion/Kconfig
@@ -1,5 +1,6 @@
 
 menu "Fusion MPT device support"
+	depends on PCI
 
 config FUSION
 	bool