drm/amdkfd: Enable userptr support when KFD is enabled

ROCm user mode depends on userptr support. Without it, KFD is basically
useless.

Make sure HSA_AMD selects the same options as DRM_AMDGPU_USERPTR to avoid
broken configurations where userptr gets enabled but its dependencies are
disabled.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Philip Yang <philip.yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>