ARM: 6520/1: Kconfig: add new symbol MIGHT_HAVE_PCI

Today more boards with arm cpu have selectable pci bus.
This patch makes this more scalable and remove line continuations in
Kconfig

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>