ARM: shmobile: only enable used I2C interfaces in DT on all Renesas boards

Currently all I2C interfaces in all *.dtsi files for various Renesas SoCs
are enabled by default. Switch them all off and only enable populated I2C
interfaces in board-specific *.dts files.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>