drm/i915/fbc: Bump ivb FBC max surface size to 4kx4k

IVB Bspec says:
"Frame Buffer Compression is only supported with memory surfaces of 4096 lines
or less and pipe source sizes of 4096 pixels by 2048 lines or less. "

so seems like we should be able to bump the offset+size limit to
at least 4kx4k. Make it so.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231117171833.25816-3-ville.syrjala@linux.intel.com


Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>