media: imx: imx7_mipi_csis: Don't pass pdev to mipi_csis_parse_dt()

The mipi_csis_parse_dt() function is called with a pointer to the
csi_state, which contains all the information necessary. Don't pass the
platform device pointer as well.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>