[media] media/v4l2: VIDEOBUF2_DMA_CONTIG should depend on HAS_DMA

m68k/sun3:
drivers/media/v4l2-core/videobuf2-dma-contig.c: In function ‘vb2_dc_mmap’:
drivers/media/v4l2-core/videobuf2-dma-contig.c:204: error: implicit declaration of function ‘dma_mmap_coherent’
drivers/media/v4l2-core/videobuf2-dma-contig.c: In function ‘vb2_dc_get_base_sgt’:
drivers/media/v4l2-core/videobuf2-dma-contig.c:387: error: implicit declaration of function ‘dma_get_sgtable’
Make VIDEOBUF2_DMA_CONTIG and VIDEO_SH_VEU (which selects the former and
doesn't have a platform dependency) depend on HAS_DMA to fix this.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>