drivers: Remove undesirable irq_enable calls from nrfx driver shims

Shims for nrfx drivers should only connect the related IRQ handlers,
they should not enable the IRQs, as this could lead to a situation
where the interrupt handler is called before the driver had a chance
to properly initialize the peripheral and install the provided event
handler. nrfx drivers will enable the interrupts appropriately on
their own by calling the NRFX_IRQ_ENABLE macro which is implemented
in nrfx_glue.h as a call to irq_enable().
This commit fixes the above issue spotted in the following shims:
- dmic_nrfx_pdm
- clock_control_nrf
- i2s_nrfx

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>

drivers/audio/dmic_nrfx_pdm.c

@@ -541,7 +541,6 @@ static const struct _dmic_ops dmic_ops = {
 	{								     \
 		IRQ_CONNECT(DT_IRQN(PDM(idx)), DT_IRQ(PDM(idx), priority),   \
 			    nrfx_isr, nrfx_pdm_irq_handler, 0);		     \
-		irq_enable(DT_IRQN(PDM(idx)));				     \
 		k_msgq_init(&dmic_nrfx_pdm_data##idx.rx_queue,		     \
 			    (char *)rx_msgs##idx, sizeof(void *),	     \
 			    ARRAY_SIZE(rx_msgs##idx));			     \