QEMU boot failed with cavs platforms

[xiulipan]

QEMU will in a IRQ storm.

irq.io: *write* 0x4 =   0x00400000 (old 0x0)    (04194304)      |.@..|
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
...
...
...
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000
irq.io: *read* at c val 0x00000000

[xiulipan]

Should be fixed by #11