fix building by adding include highmem

Change-Id: I3ebeeebb7c3c4084f8a52f36fd5ba2c8246b7480
Signed-off-by: Cedric Chaumont <cedric.chaumont@st.com>
Merge pull request #5 from cedric-chaumont-st-dev/dev/fix_include_highmem

fix building by adding include highmem
Implemented wait in normal world

- add new rpc command TEE_RPC_WAIT to enable wait in normal world
- in order to release cpu resource while waiting, invoke scheudle_timeout()
  when TEE_RPC_WAIT is received