ARM: dts: msm: Use QPNP controlled regulator devices for MSM8916

Switch out the stub regulator devices to actual qpnp-regulator
devices so that consumer requests actually control hardware state.

Since RPM control is not yet available bump up VDD_CX(S1), VDD_MX(L3)
supply regulators to max voltage.

Bump up S4 regulator to max voltage to prevent S4 going to low voltage
to respect headroom requirement of sub-regulated regulators.

Set min voltage of L10 LDO to 2.7V as all the clients connected to L10
operates at 2.7 V.

Change-Id: I6c85c334c1ba839412db9a8abe6c8c7076d483e8
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>