x86/amd-iommu: Move compl-wait command building to own function
x86/amd-iommu: Move compl-wait command building to own function

This patch introduces a seperate function for building
completion-wait commands.

Signed-off-by: Joerg Roedel <ebd221a096cbc71dd9e1991db28795933c85f380@amd.com>

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