ARM: dts: msm: set load current for regulators in Bluetooth node for SA8155

Set load current for both regulator S6A, S4C and S5C to default value
which is zero. And increase load current for regulator L15A to
let Power Management IC(PMIC) into normal power mode(NPM).
This is because drive ability of L15A is not powerful enough
if PMIC stays in low power mode(LPM). And it may lead to power
failure for external connectivity chip.

Change-Id: Ic6949d578c47d16a479d3cf30dd54abad687fb73
Signed-off-by: Yanfei Zhou <zyanfei@codeaurora.org>