Interface: Add PSA Internal Trusted Storage header

Adds version 1.0.0 of the psa/internal_trusted_storage.h header to the
include directory, as well as the psa/storage_common.h header it
depends on.

Change-Id: I6fd76eb8edb13151505351804ca73ddc14e2a0a9
Signed-off-by: Jamie Fox <jamie.fox@arm.com>