fbdev: aty: remove CONFIG_PM container

The changes made in below mentioned commit removed CONFIG_PM containers
from drivers/video/fbdev/aty/atyfb_base.c but not from
drivers/video/fbdev/aty/atyfb.h for respective callbacks.

This resulted in error for implicit declaration for those callbacks.

Fixes: 348b2956 ("fbdev: aty: use generic power management")

Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917115313.725622-1-vaibhavgupta40@gmail.com