powerpc/dts: fix lbc lack of error interrupt

P1020, P1021, P1022, P1023 when the lbc get error, the error
interrupt will be triggered. The corresponding interrupt is
internal IRQ0. So system have to process the lbc IRQ0 interrupt.

The corresponding lbc general interrupt is internal IRQ3.

Signed-off-by: Wang Dongsheng <dongsheng.wang@freescale.com>
[scottwood@freescale.com: bracketed individual list elements]
Signed-off-by: Scott Wood <scottwood@freescale.com>