ARM: shmobile: r8a7790: add VIN device nodes

Add device nodes for the four video input controllers on the R8A7790.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[Sergei: renamed VIN device nodes, edited changelog]
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>