This fixes the spurious interrupt issue on a DMA channel.

This fixes the spurious interrupt issue on a DMA channel.

    In OMAP sDMA, contrast to the SDMA.DMA4_CSRi registers, the
    SDMA.DMA4_IRQSTATUS_Lj registers are updated regardless of
    the corresponding bits in the SDMA.DMA4_IRQENABLE_Lj registers.
    Since there are four sDMA interrupt lines and if more than one
    line is actively used by two concurrently running sDMA softwares
    modules,then the spurious interrupt can be observed on the other
     lines.

    Fix in this patch will only dispatch the relevant and enabled
    interrupts on a particular line thus perevting spurious IRQ.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked By: Nishant Kamat <nskamat@ti.com>
cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>