tbs2910: prepare to synchronise device trees with linux

As a preparatory step make sure to refer to absolute node paths where
labels were removed in Linux upstream.

This avoids the following error once synchronised:

+Error: arch/arm/dts/imx6q-tbs2910-u-boot.dtsi:3.1-7 Label or path aips1
 not found
+Error: arch/arm/dts/imx6q-tbs2910-u-boot.dtsi:11.1-5 Label or path soc
 not found

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>