dmaengine: ti: k3-psil: add additional TX threads for j721e

commit b55023c75a15dc6112d50b621b89638782ecda02 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git

Add matching PSI-L threads mapping for transmission DMA channels
on the J721E platform.

Signed-off-by: Matt Ranostay <mranostay@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>