media: hantro: drop unused vb2 headers

hantro_v4l2.c includes media/videobuf2-dma-sg.h, which isn't used.
And in fact, hantro doesn't use the vb2_dma_sg_memops at all, so this
is confusing. Just drop both videobuf2 headers, they are not needed here.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>