hwrng: Add quality parameter to msm-rng driver

With the recent changes in upstream, certain parameters
are updated in the core random number generator driver.
So update HW rng driver to provide the quality estimation
of true entropy in RNG's bitstream. Value 700 corresponds
to 70% an arbitrary value, which is taken from 3.10.

Change-Id: I0d27e44a05473bcbc84af82c79565f87329b9ae7
Signed-off-by: AnilKumar Chimata <anilc@codeaurora.org>