ARM: shmobile: lager: enable i2c devices

Add i2c0, i2c1, i2c2 and i2c3 nodes to the Lager reference device tree as
these busses all have devices on them that can be probed even if they
are no drivers yet.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[horms+renesas@verge.net.au: Added shmobile to title]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>