drm/i915: allow control over the flags when migrating

drm/i915: allow control over the flags when migrating

In the next patch we want to move the object (if the current resource is
not compatible), to the mappable part of lmem for some display buffers.
Currently that requires being able to unset the I915_BO_ALLOC_GPU_ONLY
hint.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Jianshui Yu <jianshui.yu@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221004131916.233474-3-matthew.auld@intel.com
(cherry picked from commit 999f4562077208b683f0519e5f1aa1e5c2fd2191)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>