drm/i915/perf: Remove __user from u64 in drm_i915_perf_oa_config

Sparse complains that these integers from which we form void __user *,
and so we don't need the annotation itself inside the uABI.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901145729.21363-2-chris@chris-wilson.co.uk


Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>