media: rzg2l-cru: Use only frame end interrupts

media: rzg2l-cru: Use only frame end interrupts

On RZ/G3E the CRU driver relies on the frame end interrupt to detect the
completion of an active frame transfer when stopping DMA.

Update the driver to enable only frame end interrupts (CRUnIE2_FExE),
dropping the usage of the frame start interrupts, which is not required
for this operations flow.

Fix the interrupt status handling in the DMA stopping state by checking
the correct frame end status bits (FExS) instead of the frame start one
(FSxS). Add a dedicated CRUnINTS2_FExS() macro to reflect the actual
register bit layout and drop the now unused CRUnIE2_FSxE() and
CRUnINTS2_FSxS() macros.

This ensures that DMA stopping is triggered by the intended frame end
events and avoids incorrect interrupt handling.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>