[][Add mt79xx audio irq support from IRQ0-1 to IRQ0-2]

[Description]
Add mt79xx audio irq support from IRQ0-1 to IRQ0-2 and correct IRQ status.
Without this patch, it cannot support aplay and arecord simultaneously.

[Release-log]
N/A

Change-Id: I32837087e755d126e35836807730998025bfd296
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5483284
3 files changed