staging: sm7xx: smtcfb.c: Use the new PCI PM

The sm7xx driver uses the legacy PCI power management (suspend and
resume) callbacks.

This patch adds the new PCI PM and let the PCI core code handles the
PCI-specific details of power transitions.

Tested in 2.6.38, including standby and hibernation support.

Tested-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Javier M. Mellid <jmunhoz@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>