fix bugs noticed in review by @relic-se

Author: dhalbert

ports/raspberrypi/audio_dma.c

@@ -488,7 +488,7 @@ void __not_in_flash_func(isr_dma_0)(void) {
         }
         if (MP_STATE_PORT(background_pio_read)[i] != NULL) {
             rp2pio_statemachine_obj_t *pio = MP_STATE_PORT(background_pio_read)[i];
-            rp2pio_statemachine_dma_complete_write(pio, i);
+            rp2pio_statemachine_dma_complete_read(pio, i);
         }
         if (MP_STATE_PORT(background_pio_write)[i] != NULL) {
             rp2pio_statemachine_obj_t *pio = MP_STATE_PORT(background_pio_write)[i];

ports/raspberrypi/common-hal/rp2pio/StateMachine.c

@@ -1392,9 +1392,9 @@ bool common_hal_rp2pio_statemachine_background_read(rp2pio_statemachine_obj_t *s
 
     common_hal_mcu_disable_interrupts();
     // Acknowledge any previous pending interrupt
-    dma_hw->ints1 |= 1u << channel_read;
+    dma_hw->ints0 |= 1u << channel_read;
     MP_STATE_PORT(background_pio_read)[channel_read] = self;
-    dma_hw->inte1 |= 1u << channel_read;
+    dma_hw->inte0 |= 1u << channel_read;
     irq_set_mask_enabled(1 << DMA_IRQ_0, true);
     dma_start_channel_mask((1u << channel_read));
     common_hal_mcu_enable_interrupts();