[PATCH] powerpc: Kill _machine and hard-coded platform numbers

This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism.  With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.

We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants.  This commit also
changes various drivers to use the new macro instead of looking at
_machine.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index e0afb5a..0d2193b 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -296,7 +296,7 @@
 
 #ifdef CONFIG_PPC_PMAC
 		/* Disable ASIC clocks for USB */
-		if (_machine == _MACH_Pmac) {
+		if (machine_is(powermac)) {
 			struct device_node	*of_node;
 
 			of_node = pci_device_to_OF_node (dev);
@@ -331,7 +331,7 @@
 
 #ifdef CONFIG_PPC_PMAC
 	/* Reenable ASIC clocks for USB */
-	if (_machine == _MACH_Pmac) {
+	if (machine_is(powermac)) {
 		struct device_node *of_node;
 
 		of_node = pci_device_to_OF_node (dev);