refactor(rse)!: remove rse_comms_init

The function to use is now rse_mbx_init(), that does the same if
using MHU.

Change-Id: I712712d7d1bcd8c96d26951e176b877afb65209d
Signed-off-by: Yann Gautier <yann.gautier@st.com>
2 files changed