powerpc/mpic: Put "pic-no-reset" test back into the MPIC code

There's not really any reason to have this one-liner in a separate
static inline function, given that all the other similar tests are
already in the alloc_mpic() code.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>