dma: dma_nxp_edma: perform IRQ enable/disable on channel request/release

Commit 48b98a92 ("drivers: dma: dma_nxp_edma: disable IRQs when
not needed") moved the IRQ enable operation to edma_start() and added
an IRQ disable operation in edma_stop(). This is wrong because it breaks
the DMA API contract w.r.t dma_start() being `isr-ok` on imx8qm/imx8qxp.

As such, move the IRQ enable and disable operations in
dma_request_channel() and dma_release_channel().

Note1: managing the interrupts like this is only really needed when
dealing with interrupt controllers that have a power domain associated
with it (which is the case for irqstr on imx8qm/imx8qxp).

Note2: Zephyr has no reference count for shared interrupts so disabling
a shared interrupt without checking if someone else is using it is
dangerous.

Based on the aforementioned notes, the irq_disable() operation is only
performed if irqstr is used as an interrupt controller (which is only
the case for imx8qm/imx8qxp). Otherwise, the operation isn't needed.

Fixes #80573.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>