[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/ppc/platforms/prep_setup.c b/arch/ppc/platforms/prep_setup.c
index a0fc628..fa46f8c 100644
--- a/arch/ppc/platforms/prep_setup.c
+++ b/arch/ppc/platforms/prep_setup.c
@@ -1067,15 +1067,13 @@
 static int __init
 prep_request_io(void)
 {
-	if (_machine == _MACH_prep) {
 #ifdef CONFIG_NVRAM
-		request_region(PREP_NVRAM_AS0, 0x8, "nvram");
+	request_region(PREP_NVRAM_AS0, 0x8, "nvram");
 #endif
-		request_region(0x00,0x20,"dma1");
-		request_region(0x40,0x20,"timer");
-		request_region(0x80,0x10,"dma page reg");
-		request_region(0xc0,0x20,"dma2");
-	}
+	request_region(0x00,0x20,"dma1");
+	request_region(0x40,0x20,"timer");
+	request_region(0x80,0x10,"dma page reg");
+	request_region(0xc0,0x20,"dma2");
 
 	return 0;
 }