we merge the iommu initialization parameters in pci-dma.c
Nice thing, that both architectures at least recognize the same
parameters.

usedac i386 parameter is marked for deprecation
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>