[POWERPC] Spelling fixes: arch/ppc/

Spelling fixes in arch/ppc/.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc/platforms/prpmc750.h b/arch/ppc/platforms/prpmc750.h
index 4c7adcc..c4dcff0 100644
--- a/arch/ppc/platforms/prpmc750.h
+++ b/arch/ppc/platforms/prpmc750.h
@@ -16,7 +16,7 @@
 #define __ASM_PRPMC750_H__
 
 /*
- * Due to limiations imposed by legacy hardware (primaryily IDE controllers),
+ * Due to limitations imposed by legacy hardware (primarily IDE controllers),
  * the PrPMC750 carrier board operates using a PReP address map.
  *
  * From Processor (physical) -> PCI: