sunxi:pm: Fix suspend to RAM

This patch fixes crash in try to suspend to RAM for sun4i and sun5i
machines
Suspend framebuffer on sustem suspend.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Remove superfluous functions from pm.c and reindent.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Implement pm suspend.

Based on patch by Alexsey Shestacov <wingrime@gmail.com>