arm64: dts: qcom: pmi8998: add charger node

Add a node for the smb2 charger hardware found on the pmi8998 pmic
following the DT bindings.

Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230524-pmi8998-charger-dts-v2-2-2a5c77d2ff0c@linaro.org