fbdev: atyfb: use LCD management functions for PPC_PMAC also

fbdev: atyfb: use LCD management functions for PPC_PMAC also

Include PPC_PMAC in the configs that use aty_ld_lcd() and
aty_st_lcd() implementations so that the PM code may work
correctly for PPC_PMAC.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210226173008.18236-1-rdunlap@infradead.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>