powerpc/pseries: iommu cleanup
powerpc/pseries: iommu cleanup

No need to initialize per-cpu pointer to NULL, it is the default.

Direct dma ops and no setup are the defaults, no need to set for
iommu-off.

Signed-off-by: Milton Miller <8bd50e0fc26e21e23b28837d9acdf866b237c39d@bga.com>
Signed-off-by: Nishanth Aravamudan <32d5d7104760c6969dbcc939b04e64f225673f91@us.ibm.com>
Reviewed-by: Grant Likely <9069e6f5a2b566e2674a0ba1e2bf39c12c195fad@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas