dmaengine: edma: DT: Change reserved slot array from 16bit to 32bit type

commit ae0add74 upstream.

This change makes the DT file to be easier to read since the reserved slots
array does not need the '/bits/ 16' to be specified, which might confuse
some people.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>