MFC r272109, r272181:

  Replace multiple nearly-identical copies of code to walk through an FDT
  node's interrupts=<...> property creating resource list entries with a
  single common implementation.  This change makes ofw_bus_intr_to_rl() the
  one true copy of that code and removes the copies of it from other places.

  This also adds handling of the interrupts-extended property.
MFC r272333:  Honor exclusion flags when building the memory lists.
MFC r272334, r273004:

  Return the actual baud rate programmed in the hardware rather than 115200.
  This allows the "3wire" entry in /etc/ttys (with no speed specified) to work.

  Use the FIFOs in the imx5/imx6 uart hardware instead of interrupting on
  each byte sent or received.
MFC r273282:  Fail to probe on simplebus nodes that lack a "ranges" property.
MFC r273283:

  Attach this driver during BUS_PASS_BUS and move the cpu init code to a
  bus_new_pass() handler so it doesn't happen until BUS_PASS_CPU.  This allows
  the anatop driver to outbid the generic simplebus driver (which the FDT
  data describes as compatible).
MFC r273298:

  The U-Boot README says fdt_addr_r is the right env var for fdt data
  loaded into ram, but vendors also use fdtaddr and fdt_addr.  Check the
  recommended variable first and fall back to the others.
MFC r273352:  Ask for the fastest available clock for the GTP timecounter.
MFC r273353, r273514:

  Attach the imx6 CCM driver during BUS_PASS_CPU.

  Unconditionally enable the clocks for all imx6 devices that we have drivers
  for, or that are required to run the chip (such as busses).