Introduce CONFIG_VIRT_TO_BUS

Make some offending drivers depend on it and set CONFIG_ARCH_NO_VIRT_TO_BUS
for ppc64 so that we don't build those drivers.

This gets PowerPC allmodconfig and allyesconfig much closer to building.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@ftp.linux.org.uk>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/message/i2o/Kconfig b/drivers/message/i2o/Kconfig
index bfa5ece..5afa0e3 100644
--- a/drivers/message/i2o/Kconfig
+++ b/drivers/message/i2o/Kconfig
@@ -54,6 +54,7 @@
 
 config I2O_CONFIG
 	tristate "I2O Configuration support"
+	depends on VIRT_TO_BUS
 	---help---
 	  Say Y for support of the configuration interface for the I2O adapters.
 	  If you have a RAID controller from Adaptec and you want to use the