Add R5 specific dts for am654-evm.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Schuyler Patton <spatton@ti.com>
Signed-off-by: James Doublesin <doublesin@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>