arm64: dts: qcom: sdm845-lg-{judyln, judyp}: Reference memory region in fb

arm64: dts: qcom: sdm845-lg-{judyln, judyp}: Reference memory region in fb

To prevent duplicating the framebuffer address and size point out the
existing framebuffer memory region instead of specifying the address
manually.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Paul Sajna <sajattack@postmarketos.org>
Reviewed-by: David Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20260408-judyln-followup-v1-3-823467519b59@postmarketos.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>