Remove the C and platform device version of KZM9D.

The DT version of KZM9D board support can now instead
directly be used with SoC specific code in setup-emev2.c.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>