[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/arch/powerpc/platforms/powermac/pci.c b/arch/powerpc/platforms/powermac/pci.c
index de3f30e..f5d8d15 100644
--- a/arch/powerpc/platforms/powermac/pci.c
+++ b/arch/powerpc/platforms/powermac/pci.c
@@ -1201,7 +1201,7 @@
 #ifdef CONFIG_PPC32
 void pmac_pci_fixup_cardbus(struct pci_dev* dev)
 {
-	if (_machine != _MACH_Pmac)
+	if (!machine_is(powermac))
 		return;
 	/*
 	 * Fix the interrupt routing on the various cardbus bridges
@@ -1244,8 +1244,9 @@
         * On PowerMacs, we try to switch any PCI ATA controller to
 	* fully native mode
         */
-	if (_machine != _MACH_Pmac)
+	if (!machine_is(powermac))
 		return;
+
 	/* Some controllers don't have the class IDE */
 	if (dev->vendor == PCI_VENDOR_ID_PROMISE)
 		switch(dev->device) {