[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>

arch/powerpc/platforms/powermac/pfunc_base.c

@@ -336,6 +336,8 @@ int __init pmac_pfunc_base_install(void)
 		return 0;
 	pfbase_inited = 1;
 
+	if (!machine_is(powermac))
+		return 0;
 
 	DBG("Installing base platform functions...\n");