HID: picolcd: Add missing #include <linux/uaccess.h>

m68k/allmodconfig:

drivers/hid/hid-picolcd_debugfs.c: In function ‘picolcd_debug_reset_write’:
drivers/hid/hid-picolcd_debugfs.c:54: error: implicit declaration of function ‘copy_from_user’
drivers/hid/hid-picolcd_debugfs.c: In function ‘picolcd_debug_eeprom_read’:
drivers/hid/hid-picolcd_debugfs.c:112: error: implicit declaration of function ‘copy_to_user’

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>