powerpc/cell: Make axonram depends on BLOCK

Fix axonram driver dependency

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 68b9b8f..ffa2a9f 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -269,7 +269,7 @@
 
 config AXON_RAM
 	tristate "Axon DDR2 memory device driver"
-	depends on PPC_IBM_CELL_BLADE
+	depends on PPC_IBM_CELL_BLADE && BLOCK
 	default m
 	help
 	  It registers one block device per Axon's DDR2 memory bank found