IB/ipath: Add flag and handling for chips with swapped register bug

The 6110 had a bug that caused some registers to be swapped; it was
fixed for the 7220 (and didn't affect the 6120 because it had fewer
registers).  This adds a flag and related code to handle that, and
includes some minor cleanups in the same area.

Signed-off-by:  Ralph Campbell <ralph.campbell@qlogic.com>
diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index b9cca84..e07df00 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -756,6 +756,7 @@
 #define IPATH_DISABLED      0x80000 /* administratively disabled */
 		/* Use GPIO interrupts for new counters */
 #define IPATH_GPIO_ERRINTRS 0x100000
+#define IPATH_SWAP_PIOBUFS  0x200000
 
 /* Bits in GPIO for the added interrupts */
 #define IPATH_GPIO_PORT0_BIT 2