powerpc/mpic: Support compiling with DEBUG enabled

Support compilation of mpic.c with DEBUG defined, as now we have irq_desc and
not irq number.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1 file changed