drm/i915: Pass intel_atomic_state instead of drm_atomic_state

No functional changes, to align with previous cleanups pass
intel_atomic_state instead of drm_atomic_state.
Also pass this intel_atomic_state with crtc_state to
some of the atomic_check functions.

v2:
* Squash some changes from next patch (Ville)

Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201113155656.17630-1-manasi.d.navare@intel.com