USB: add ehci-ppc-of bus glue (device-tree aware)

This adds device-tree-aware ehci-ppc-of driver.
The code is based on the ehci-ppc-soc driver by
Stefan Roese <sr@denx.de>.

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Stefan Roese <sr@denx.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index eeda4c8..c78c527 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -741,7 +741,7 @@
  * definition below can die once the 4xx support is
  * finally ported over.
  */
-#if defined(CONFIG_PPC)
+#if defined(CONFIG_PPC) && !defined(CONFIG_PPC_MERGE)
 #define readl_be(addr)		in_be32((__force unsigned *)addr)
 #define writel_be(val, addr)	out_be32((__force unsigned *)addr, val)
 #endif