Limit DMA address space to 1GB since the trident audio cards can't handle DMA addresses located above 1GB. The LBA(loop begin address) register which holds DMA base address is 32bits register. But the MSB 2bits are used for other purposes. This effectivly limits the DMA address space up to 1GB.
Limit DMA address space to 1GB since the trident audio cards can't
handle DMA addresses located above 1GB. The LBA(loop begin address)
register which holds DMA base address is 32bits register. But the
MSB 2bits are used for other purposes. This effectivly limits the
DMA address space up to 1GB.

Approved by:	jake (mentor)
Reviewed by:	truckman, matk

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