Use device tree to determine if we actually have an MPIC and use
CPU feature to decide if we should use doorbells for IPIs.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

There is a call to local_irq_restore in the normal exit case, so it would
seem that there should be one on an error return as well.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression l;
expression E,E1,E2;
@@

local_irq_save(l);
... when != local_irq_restore(l)
    when != spin_unlock_irqrestore(E,l)
    when any
    when strict
(
if (...) { ... when != local_irq_restore(l)
               when != spin_unlock_irqrestore(E1,l)
+   local_irq_restore(l);
    return ...;
}
|
if (...)
+   {local_irq_restore(l);
    return ...;
+   }
|
spin_unlock_irqrestore(E2,l);
|
local_irq_restore(l);
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Added 85xx specifc smp_ops structure.  We use ePAPR style boot release
and the MPIC for IPIs at this point.

Additionally added routines for secondary cpu entry and initializtion.
Signed-off-by: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NTrent Piepho <tpiepho@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>