drivers: dma_qmsi: Wait few cycles to allow DMA controller changes

Add few nop instructions to allow the DMA controller settle,
It takes time after starting the transfer to access the DMA
controller registers, so a few cycles are added, the minimal number
of cycles needed has been calculated using tests results on c1000
development board.

Jira: ZEP-1803

Change-Id: I1f8e8478f0350e1b6e4dd596b783dc4babc2d02b
Signed-off-by: Sergio Rodriguez <sergio.sf.rodriguez@intel.com>