ibmvnic: Fix ibmvnic_capability struct

The ibmvnic_capability struct was defined incorrectly. The last two
elements of the struct are in the wrong order.  In addition, the number
element should be 64-bit. Byteswapping functions are updated
as well.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>