V4L/DVB (10176b): pxa-camera: fix redefinition warnings and missing DMA definitions

1. now pxa_camera.c uses ioremap() for register access, pxa_camera.h is
   totally useless. Remove it.

2. <asm/dma.h> does no longer include <mach/dma.h>, include the latter
   file explicitly

 delete mode 100644 drivers/media/video/pxa_camera.h

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>