arm64: dts: qcom: db820c: Move blsp1_uart2 pin states to msm8996.dtsi

Move blsp1_uart2_default and blsp1_uart2_sleep to the SoC device tree to
avoid duplicating them in other device trees.

Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210901193214.250375-2-y.oudjana@protonmail.com