msm: rpm-smd: add missing kvp in sleep set

There is a bug in the RPM SMD driver where it misses to
add a KVP to sleep node, if the KVP was not present in first
sleepset it received. Hence it misses the new KVPs that are
sent subsequently for sleep set. This results in improper
configuration of the resource at RPM. Code is modified to add
the new KVP to the sleep set in these scenarios.

CRs-fixed: 546434
Change-Id: I43301f93fb48535e3d4a0833333568488a2c33d3
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>