mmc: omap_hsmmc: split omap-dma header file

moving dmaengine consumer specific function to omap-dmaengine.h
to Resolve build failure seen with sh-allmodconfig:
    include/linux/omap-dma.h:171:8: error: expected identifier before numeric constant
    make[4]: *** [drivers/mmc/host/omap_hsmmc.o] Error 1

Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Balaji T K <balajitk@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>