[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>

fs/partitions/mac.c

@@ -12,6 +12,7 @@
 #include "mac.h"
 
 #ifdef CONFIG_PPC_PMAC
+#include <asm/machdep.h>
 extern void note_bootable_part(dev_t dev, int part, int goodness);
 #endif
 
@@ -79,7 +80,7 @@ int mac_partition(struct parsed_partitions *state, struct block_device *bdev)
 		 * If this is the first bootable partition, tell the
 		 * setup code, in case it wants to make this the root.
 		 */
-		if (_machine == _MACH_Pmac) {
+		if (machine_is(powermac)) {
 			int goodness = 0;
 
 			mac_fix_string(part->processor, 16);