ARM: dts: Enable PMIC idle configuration for LDP

With the IO chain reconfigure fixed, we can now enable the PMIC
scripts for LDP.

Note that at least on my es3.0 based LDP, the UART seems to be
flakey after wake-up events from off-idle and hangs but eventually
continues.

Signed-off-by: Tony Lindgren <tony@atomide.com>