myri10ge: fix most sparse warnings

- convert remaining htonl/ntohl +__raw_read/__raw_writel to
  swab32 + readl/writel
- add missing __iomem qualifier in myri10ge_open()
- fix  dubious: x & !y warning by switching from logical to bitwise not

The swab32 conversion fixes a bug in myri10ge_led() where
big-endian machines would write the wrong pattern.

The only remaining warning (lock context imbalance) is due to
the use of __netif_tx_trylock(), and cannot easily be fixed.

Signed-off-by: Andrew Gallatin <gallatin@myri.com>
Signed-off-by: David S. Miller <davem@davemloft.net>