powerpc: Fix misspellings in comments.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 3f191f5..5c38e49 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -174,11 +174,11 @@
 	   platform, called once per cpu. */
 	void		(*enable_pmcs)(void);
 
-	/* Set DABR for this platform, leave empty for default implemenation */
+	/* Set DABR for this platform, leave empty for default implementation */
 	int		(*set_dabr)(unsigned long dabr,
 				    unsigned long dabrx);
 
-	/* Set DAWR for this platform, leave empty for default implemenation */
+	/* Set DAWR for this platform, leave empty for default implementation */
 	int		(*set_dawr)(unsigned long dawr,
 				    unsigned long dawrx);