video: fbdev: sh_mobile_lcdcfb: fix error return code in sh_mobile_lcdc_probe()

Fix to return error code -ENOMEM from the ioremap_nocache() error
handling case instead of 0, as done elsewhere in this function.

Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>