carma: remove unnecessary DMA_INTERRUPT capability

These drivers set the DMA_INTERRUPT capability bit when requesting a DMA
controller channel. This was historical, and is no longer needed.

Recent changes to the drivers/dma/fsldma.c driver have removed support
for this flag. This makes the carma drivers unable to find a DMA channel
with the required capabilities.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>