MIPS: Octeon: Add PCIe2 support in arch_setup_msi_irq()

In arch_setup_msi_irq(), there is no case for PCIe2. So board which have PCIe2 functionality
fails to boot with "Kernel panic - not syncing: arch_setup_msi_irq: Invalid octeon_dma_bar_type"
message. This patch solve this problem.

Signed-off-by: Eunbong Song <eunb.song@samsung.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/6747/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>