drm/i915/display: Configure the second scaler

drm/i915/display: Configure the second scaler

Both sharpness and panel fitter use pipe scaler,
but only one can be enabled at a time. Furthermore
sharpness uses second scaler. So for CASF, check if
second scaler is available and make sure that only
either of panel fitter or sharpness is enabled at
a time.

v2: Add the panel fitting check before enabling sharpness
v3: Reframe commit message[Arun]
v4: Replace string based comparison with plane_state[Jani]
v5: Rebase
v6: Fix build issue
v7: Remove scaler id from verify_crtc_state[Ankit]
v8: Change the patch title. Add code comment.
    Move the config part in patch#6. [Ankit]
v9: Refactor the patch[Ankit]
v10: Modify the header of patch[Ankit]

Signed-off-by: Nemesa Garg <nemesa.garg@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20251028120747.3027332-8-ankit.k.nautiyal@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>