ARM: dts: sbc-t3x30: remove unneded unit names

This patch fixes the following DTC warnings for omap3-sbc-t3517.dtb,
omap3-sbc-t3530.dtb and omap3-sbc-t3730.dtb:

"encoder@0 has a unit name, but no reg property"
"endpoint@0 has a unit name, but no reg property"
"connector@0 has a unit name, but no reg property"

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>