drm/i915/fbc: dirty rect support for FBC

drm/i915/fbc: dirty rect support for FBC

Dirty rectangle feature allows FBC to recompress a subsection
of a frame. When this feature is enabled, display will read
the scan lines between dirty rectangle start line and dirty
rectangle end line in subsequent frames.

Use the merged damage clip stored in the plane state to
configure the FBC dirty rect areas.

v2: - Move dirty rect handling to fbc state (Ville)

v3: - Use intel_fbc_dirty_rect_update_noarm (Ville)
    - Split plane damage collection and dirty rect preparation
    - Handle case where dirty rect fall outside the visible region

v4: - A state variable to check if we need to update dirty rect
    registers in case intel_fbc_can_flip_nuke() (Ville)

v5: - No need to use a separate valid flag, updates to the
      conditions for prepare damage rect (Ville)
    - Usage of locks in fbc dirty rect related functions (Ville)

v6: - updates dirty rect handling (Ville)

v7: - Loop through all planes in atomic state is good enough (Ville)

Bspec: 68881, 71675, 73424
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250228093802.27091-8-vinod.govindapillai@intel.com