dmaengine: sh: rz-dmac: Add device_{pause,resume}() callbacks

dmaengine: sh: rz-dmac: Add device_{pause,resume}() callbacks

The RZ/G2L SCIFA driver uses dmaengine_prep_slave_sg() to enqueue DMA
transfers and implements a timeout mechanism on RX to handle cases where
a DMA transfer does not complete. The timeout is implemented using an
hrtimer.

In the hrtimer callback, dmaengine_tx_status() is called (along with
dmaengine_pause()) to retrieve the transfer residue and handle incomplete
DMA transfers.

Add support for device_{pause, resume}() callbacks.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://patch.msgid.link/20260316133252.240348-9-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>