msm: board-8930: Increase LDO 20 voltage request from 1.2 V to 1.25 V

Hardware characterization has shown that memory stability
improves when the DDR supply voltage (provided by LDO 20) is
increased to 1.25 V. Therefore, increase the voltage constraints
for LDO 20 so that 1.25 V is requested. This also requires
modifying the voltages requested by the consumers of LDO 20.
LDO 20 is used by the Sitar audio CODEC.

Change-Id: Ia2fb75b509ea96d25bfacbcf9a14561b1b439f9e
Signed-off-by: David Collins <collinsd@codeaurora.org>