arm64: dts: qcom: sm8150-kumano: Panel framebuffer is 2.5k instead of 4k

The framebuffer configuration for kumano griffin, written in kumano dtsi
(which is overwritten in bahamut dts for its smaller panel) has to use a
1096x2560 configuration as this is what the panel (and framebuffer area)
has been initialized to.  Downstream userspace also has access to (and
uses) this 2.5k mode by default, and only switches the panel to 4k when
requested.

Fixes: d0a6ce59 ("arm64: dts: qcom: sm8150: Add support for SONY Xperia 1 / 5 (Kumano platform)")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221209191733.1458031-1-marijn.suijten@somainline.org