powerpc: remove CONFIG_PPC_ISERIES from the architecture Kconfig files

After this, we can remove the legacy iSeries code more easily.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 0cfb46d..236ab67 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -2,7 +2,6 @@
 
 source "arch/powerpc/platforms/powernv/Kconfig"
 source "arch/powerpc/platforms/pseries/Kconfig"
-source "arch/powerpc/platforms/iseries/Kconfig"
 source "arch/powerpc/platforms/chrp/Kconfig"
 source "arch/powerpc/platforms/512x/Kconfig"
 source "arch/powerpc/platforms/52xx/Kconfig"
@@ -138,7 +137,7 @@
 	  of the register contents in software.
 
 config IBMVIO
-	depends on PPC_PSERIES || PPC_ISERIES
+	depends on PPC_PSERIES
 	bool
 	default y