83xx/85xx/86xx: LBC register cleanup

Currently, 83xx, 86xx, and 85xx have a lot of duplicated code
dedicated to defining and manipulating the LBC registers.  Merge
this into a single spot.

To do this, we have to decide on a common name for the data structure
that holds the lbc registers - it will now be known as fsl_lbc_t, and we
adopt a common name for the immap layouts that include the lbc - this was
previously known as either im_lbc or lbus; use the former.

In addition, create accessors for the BR/OR regs that use in/out_be32
and use those instead of the mismash of access methods currently in play.

I have done a successful ppc build all and tested a board or two from
each processor family.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>