powerpc: Fix typo introduced in merging platform codes

Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-powerpc/processor.h

@@ -78,14 +78,11 @@ extern unsigned char ucBoardRevMaj, ucBoardRevMin;
 /*
  * iSeries is soon to become MULTIPLATFORM hopefully ...
  */
-#define _machine CONFIG_PPC_ISERIES_LPAR
+#define _machine PLATFORM_ISERIES_LPAR
 #else
 #define _machine 0
 #endif /* CONFIG_PPC_MULTIPLATFORM */
 
-
-
-
 /*
  * Default implementation of macro that returns current
  * instruction pointer ("program counter").