V4L/DVB: tlg2300: cleanups when power management is not configured

When power management is not configured (CONFIG_PM) then some code is no longer
necessary.

This patch will remove the following compiler warnings:
 * pd-dvb.c: In function 'poseidon_fe_release':
 * pd-dvb.c:101: warning: unused variable 'pd'
 * pd-video.c:14: warning: 'pm_video_suspend' declared 'static' but never defined
 * pd-video.c:15: warning: 'pm_video_resume' declared 'static' but never defined

Signed-off-by: Márton Németh <nm127@freemail.hu>
Acked-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>