media: imx: imx7-media-csi: Merge all config in imx7_csi_configure()

Merge all the configuration steps (imx7_csi_buf_stride_set(),
imx7_csi_deinterlace_enable(), imx7_csi_set_imagpara() and
imx7_csi_init_default()) in the imx7_csi_configure() function. This
simplifies the configuration procedure by removing most
read-update-write cycles, and makes the code generally more readable.

imx7_csi_init_default() is kept as it is also called from
imx7_csi_deinit(). This will be addressed separately.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>