dt-bindings: arm: consistently name r8a77965 as M3-N

There is an inconsistency between the use of M3N and M3-N.
This patch resolves this by consistently using the latter.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Rob Herring <robh@kernel.org>
1 file changed