MFC r269502:
Fix an overflow in getsockopt(). optval isn't big enough to hold
sbintime_t.
Re-introduce r255030 behaviour capping socket timeouts to INT_32
if they're too large.
MFC 259907 (dates back to december)
use the correct netmap <-> nic slot mapping on the transmit ring for 'lem'.
This bug would manifest only in netmap mode and on packets transmitted after
a NIC reset while netmap mode is active.
MFC r266922:

  Add a bounds verification to the SCL and SDA pin values.

  At attach, print the SCL and SDA pin numbers.

  Remove a stray blank line.

  Remove the GPIOBUS locking from gpioiic_reset(), it is already called with
  this lock held.  This fixes a crash when you try to scan the iicbus with
  i2c(8).