msm: apr: unblock the apr calls post SSR if the modem is not loaded

After the SSR is triggered, following apr commands waits for
the modem to be loaded back and hence adds to the latency.
Fix by unblocking the apr call if the modem is not yet loaded.

CRs-Fixed: 663477
Change-Id: Id4228e5b24f80813b38ef7d0634eb05c016b856b
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>
Signed-off-by: Fred Oh <fred@codeaurora.org>