Update the EMEV2 struct map_desc to exclude the SMU
and also include the ->map_io() callback in the DT
version of EMEV2 board support.

The EMEV2 SMP code can these days perform ioremap()
early on without the SMU information in the io_desc[].

To correctly support SMP in case of DT-only board
support then the ->map_io() callback is needed.
Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>