HID: picolcd: fix build error if !CONFIG_DEBUG_FS

Current code missed the definition for picolcd_debug_out_report, but add
definition for picolcd_debug_raw_event twice.

This patch fixes below build error:
  CC [M]  drivers/hid/hid-picolcd_core.o
In file included from drivers/hid/hid-picolcd_core.c:34:0:
drivers/hid/hid-picolcd.h:176:20: error: redefinition of 'picolcd_debug_raw_event'
drivers/hid/hid-picolcd.h:162:20: note: previous definition of 'picolcd_debug_raw_event' was here
make[2]: *** [drivers/hid/hid-picolcd_core.o] Error 1
make[1]: *** [drivers/hid] Error 2
make: *** [drivers] Error 2

if CONFIG_DEBUG_FS is unset.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>