sh: explicitly include sh_dma.h in setup-sh7722.c

setup-sh7722.c defines several objects, whose types are defined in
sh_dma.h, so, it has to be included explicitly.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>