dmaeninge: xilinx_dma: Fix bug in multiple frame stores scenario in vdma

VDMA engine default frame buffer configuration is cirular mode.
in this mode dmaengine continuously circles through h/w configured fstore
frame buffers.

When vdma h/w is configured for more than one frame.
for example h/w is configured for n number of frames, user
submits less than n number of frames and triggered the dmaengine
using issue_pending API.

since the h/w (or) driver default configuraiton is circular mode
h/w tries to write/read from an invalid frame buffer resulting
errors from the vdma dmaengine.

This patch fixes this issue by enabling the park mode as
default mode configuration for frame buffers in s/w,
so that driver can handle all cases for "k" frames where n%k==0
(n is a multiple of k) by simply replicating the frame pointers.

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>