icnss: Add size check before assigning msa permission

While assigning msa permission, number of memory region is passed
as an argument within platform private data. This number could
exceed the range of memory region buffer that preallocated. Hence
add size check before accessing region buffer.

Change-Id: I45f4efc7edaa636c861458dab74b1956767d2019
CRs-Fixed: 2101134
Signed-off-by: Yuanyuan Liu <yuanliu@codeaurora.org>