arm64: dts: qcom: add apq8096sg-db820c, AP8096SG variant of DB820c

arm64: dts: qcom: add apq8096sg-db820c, AP8096SG variant of DB820c

There has been a (rare) variant of Dragonboard 820c, utilizing Pro
version of the SoC, with the major difference being CPU and GPU clock
tables. Add a DT file representing this version of the board.

01:13:26.275: B -    417880 - 8996 Pro v1.x detected, Max frequency = 1.8 GHz

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251111-db820c-pro-v1-2-6eece16c5c23@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>