fbdev: Clean up include statements in header file

Include mutex.h, printk.h and types.h, remove several unnecessary
include statements, and sort the list alphabetically.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240219093941.3684-10-tzimmermann@suse.de