dmaengine: bcm2835: fix unexported function

The bcm2835_dma_prep_dma_memcpy() function is not exported
outside the driver, so make it static to avoid the following
warning:

drivers/dma/bcm2835-dma.c:616:32: warning: symbol 'bcm2835_dma_prep_dma_memcpy' was not declared. Should it be static?

Signed-off-by: Ben Dooks <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>
Signed-off-by: Vinod Koul <[email protected]>
1 file changed