lima/gpir: Always schedule complex2 and *_impl right after complex1

lima/gpir: Always schedule complex2 and *_impl right after complex1

See https://gitlab.freedesktop.org/lima/mesa/issues/94 for the gory
details of why this is needed. For *_impl this is easy, since it never
increases register pressure and it goes in the complex slot hence it
never counts against max nodes. It's a bit more challenging for
complex2, since it does count against max nodes, so we need to change
the reservation logic to reserve an extra slot for complex2 when
scheduling complex1. This second part isn't strictly necessary yet, but
it will be for exp2.

Signed-off-by: Connor Abbott <cwabbott0@gmail.com>
Acked-by: Qiang Yu <yuq825@gmail.com>