ARM: dts: db600c: add pmic regulator supplies

This patch adds pmic regulator supplies connected on the board.
Rest of the invidual regulators would be added as and when required by
the devices.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>