video: ocfb: Use devm_platform_ioremap_resource() in ocfb_probe()

Simplify this function implementation by using a known wrapper function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/61b75aa6-ff92-e0ed-53f2-50a95d93d1f6@web.de