drm/radeon/kms/pm: add additional asic callbacks

- pm_misc() - handles voltage, pcie lanes, and other non
clock related power mode settings.  Currently disabled.
Needs further debugging

- pm_prepare() - disables crtc mem requests right now.
All memory clients need to be disabled when changing
memory clocks.  This function can be expanded to include
disabling fb access as well.

- pm_finish() - enable active memory clients.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/evergreen_reg.h b/drivers/gpu/drm/radeon/evergreen_reg.h
index 9dba6d9..93aab2e 100644
--- a/drivers/gpu/drm/radeon/evergreen_reg.h
+++ b/drivers/gpu/drm/radeon/evergreen_reg.h
@@ -166,6 +166,7 @@
 /* CRTC blocks at 0x6df0, 0x79f0, 0x105f0, 0x111f0, 0x11df0, 0x129f0 */
 #define EVERGREEN_CRTC_CONTROL                          0x6e70
 #       define EVERGREEN_CRTC_MASTER_EN                 (1 << 0)
+#       define EVERGREEN_CRTC_DISP_READ_REQUEST_DISABLE (1 << 24)
 #define EVERGREEN_CRTC_STATUS                           0x6e8c
 #define EVERGREEN_CRTC_UPDATE_LOCK                      0x6ed4