ARM: dts: k2g: Add DCAN nodes

Add nodes for the two DCAN instances included in 66AK2G

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[d-gerlach@ti.com: add power-domains and clock information]
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
[fcooper@ti.com: update subject and commit message. Misc minor updates]
Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>