raw/ioat: expand descriptor struct to full 64 bytes

Although it's unused by the driver, add the interrupt handle field in
the descriptor to the descriptor structure for completeness, and
explicitly add the reserved padding field on the end of the structure
too. This means that when a descriptor is defined on the stack, or
initialized by the compiler, the unused/reserved space will be zeroed
appropriately.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

drivers/raw/ioat/rte_ioat_rawdev_fns.h

@@ -140,7 +140,10 @@ struct rte_idxd_hw_desc {
 
 	uint32_t size;    /* length of data for op, or batch size */
 
-	/* 28 bytes of padding here */
+	uint16_t intr_handle; /* completion interrupt handle */
+
+	/* remaining 26 bytes are reserved */
+	uint16_t __reserved[13];
 } __rte_aligned(64);
 
 /**