linux-phytec-ti

powerpc/xics: Use hwirq for xics domain irq number

To try to avoid future confusion, rename irq to hwirq when it refers
to a xics domain number instead of a linux irq number.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>