Input: sh_keysc - fix compile warning

The "#if" above should really be an "#ifdef" to avoid this warning:

  CC      drivers/input/keyboard/sh_keysc.o
drivers/input/keyboard/sh_keysc.c:294:5: warning: "CONFIG_PM_SLEEP" is
not defined

Reported-by: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>