Select VIRT_TO_BUS directly where needed

In commit 887cbce0adea ("arch Kconfig: centralise ARCH_NO_VIRT_TO_BUS")
I introduced the config sybmol HAVE_VIRT_TO_BUS and selected that where
needed.  I am not sure what I was thinking.  Instead, just directly
select VIRT_TO_BUS where it is needed.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b89d7eb..8082151 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -98,7 +98,7 @@
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select SYSCTL_EXCEPTION_TRACE
 	select ARCH_WANT_OPTIONAL_GPIOLIB
-	select HAVE_VIRT_TO_BUS if !PPC64
+	select VIRT_TO_BUS if !PPC64
 	select HAVE_IDE
 	select HAVE_IOREMAP_PROT
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS