dt-bindings: Add binding for img,vxe384 for J721E

commit 8a013785d4c6022c85bd8947bd5e594eeca0c85a from
TI Linux SDK PROCESSOR-SDK-LINUX-J721E_07.03.00.05

Add the dt-binding for the img,vxe384 node for J721E.

Signed-off-by: Angela Stegmaier <angelabaker@ti.com>
Reviewed-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Sidraya Jayagond <sidraya.bj@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>