msm: pil-q6v4: Ramp up Q6 core voltage in two steps

Hardware profiling suggests a potential need to ramp up the Q6
core voltage in two steps, rather than jumping immediately to
1.05V.

Pick an intermediate step of 375mV and stay there for at least
100us before ramping up the rest of the way.

Change-Id: I64b13e4ae54ed584d6228ad9fb00baa443aca6d0
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>