ARM: dts: armada-38x: use the new thermal binding

Commit 2f28e4c2 (thermal: armada: Clarify control registers
accesses) introduced the new thermal binding. The new binding extends
the second registers field size to 8. Switch to the new binding to fix
thermal reading values. Without this change the fix for errata #132698
introduced in commit 8c0b888f

 (thermal: armada: Change sensors trim
default value) has no effect.

Cc: stable@vger.kernel.org # v4.16+
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>