drm/radeon/kms: add query for crtc hw id from crtc id to get info V2

Userspace need to know the hw crtc id (0, 1, 2, ...) from the drm
crtc id. Bump the minor version so userspace can enable conditionaly
features depend on this.

V2 use num_crtc and avoid DRM_ERROR

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>