Right now the error messages when optee has a version mismatch or shared
memory is not configured are done with a debug().
That's not very convenient since you have to enable debugging to figure
out what's going on, although this is an actual error.
So let's switch the debug() -> dev_err() and report those explicitly.
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>