Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS

Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS

Make it easier for more architectures to select it and thus disable
drivers that use virt_to_bus().

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: H Hartley Sweeten <hartleys@visionengravers.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>