powerpc/hvc: Driver build breaks with !HVC_CONSOLE

Hi Stephen,

	next-20090925 randconfig build breaks on hvcs driver on powerpc,
with HVC_CONSOLE=n.

ERROR: ".hvc_put_chars" [drivers/char/hvcs.ko] undefined!
ERROR: ".hvc_get_chars" [drivers/char/hvcs.ko] undefined!

adding the dependency of HVC_CONSOLE helped
Signed-off-by: NKamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/char/Kconfig

@@ -669,7 +669,7 @@ config VIRTIO_CONSOLE
 
 config HVCS
 	tristate "IBM Hypervisor Virtual Console Server support"
-	depends on PPC_PSERIES
+	depends on PPC_PSERIES && HVC_CONSOLE
 	help
 	  Partitionable IBM Power5 ppc64 machines allow hosting of
 	  firmware virtual consoles from one Linux partition by