To accomodate the extra planes, the bit definitions were shuffled around
a bit.

v2: Rebase on top of the for_each_pipe() change adding dev_priv as first
    argument.
v3: Rebase after yet another change int that area (done with wiggle)
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>