msm: adsprpc: Reserve contexts for all static handles

Current code has contexts reserved only for kernel calls. If the
context table is full during static handle invocation, it results
in complete feature failure and hang. Reserve contexts in the context
table for all kernel and static handle invocations.

Change-Id: I21a6de9af86129beede059a66c5b41343d2b5a51
Signed-off-by: Himateja Reddy <hmreddy@codeaurora.org>