davinci: add arch_ioremap() which uses existing static mappings

Add arch-specific ioremap() which uses any existing static mappings in
place of doing a new mapping.  From now on, drivers should always use
ioremap() instead of IO_ADDRESS().

In addition, remove the davinci_[read|write]* macros in favor of using
ioremap.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-davinci/usb.c b/arch/arm/mach-davinci/usb.c
index 2429b79..abedb63 100644
--- a/arch/arm/mach-davinci/usb.c
+++ b/arch/arm/mach-davinci/usb.c
@@ -14,6 +14,8 @@
 #include <mach/hardware.h>
 #include <mach/irqs.h>
 
+#define DAVINCI_USB_OTG_BASE 0x01C64000
+
 #if defined(CONFIG_USB_MUSB_HDRC) || defined(CONFIG_USB_MUSB_HDRC_MODULE)
 static struct musb_hdrc_eps_bits musb_eps[] = {
 	{ "ep1_tx", 8, },