[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/macintosh/adb.c b/drivers/macintosh/adb.c
index d2ead17..781d93b 100644
--- a/drivers/macintosh/adb.c
+++ b/drivers/macintosh/adb.c
@@ -42,6 +42,7 @@
 #include <asm/semaphore.h>
 #ifdef CONFIG_PPC
 #include <asm/prom.h>
+#include <asm/machdep.h>
 #endif
 
 
@@ -294,7 +295,7 @@
 	int i;
 
 #ifdef CONFIG_PPC32
-	if ( (_machine != _MACH_chrp) && (_machine != _MACH_Pmac) )
+	if (!machine_is(chrp) && !machine_is(powermac))
 		return 0;
 #endif
 #ifdef CONFIG_MAC