video: fbdev: mmp: Fix kernel-doc warning for lcd_spi_write

Add missing parameter and drop parameter that is not present

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201206190247.1861316-8-sam@ravnborg.org