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/hydra.h b/arch/powerpc/include/asm/hydra.h
index 1cb39c9..b3b0f2d 100644
--- a/arch/powerpc/include/asm/hydra.h
+++ b/arch/powerpc/include/asm/hydra.h
@@ -89,7 +89,7 @@
 #define HYDRA_INT_EXT2		13	/* PCI IRQX */
 #define HYDRA_INT_EXT3		14	/* PCI IRQY */
 #define HYDRA_INT_EXT4		15	/* PCI IRQZ */
-#define HYDRA_INT_EXT5		16	/* IDE Primay/Secondary */
+#define HYDRA_INT_EXT5		16	/* IDE Primary/Secondary */
 #define HYDRA_INT_EXT6		17	/* IDE Secondary */
 #define HYDRA_INT_EXT7		18	/* Power Off Request */
 #define HYDRA_INT_SPARE		19