arm64: dts: qcom: pms405: Add pon and pwrkey nodes

PMS405 also features PON block, so add PON and PWRKEY nodes

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>