irqchip/bcm2836: Drop extra memory barrier in SMP boot.

The writel() immediately after this has a barrier, anyway.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://lkml.kernel.org/r/1454620468-31303-1-git-send-email-eric@anholt.net


Signed-off-by: Jason Cooper <jason@lakedaemon.net>