[media] ir-hix5hd2 fix build warning

Change CONFIG_PM to CONFIG_PM_SLEEP to solve
warning: 'hix5hd2_ir_suspend' & 'hix5hd2_ir_resume' defined but not used

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>