arm/dts: k3-j7200-r5-common: Add VTM node

Add voltage and thermal management (VTM) node. The efuse values for the
OPPs are stored under the VTM, and is needed for AVS class 0 support.

Signed-off-by: Gowtham Tammana <g-tammana@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210714205300.17424-4-g-tammana@ti.com