drm/radeon/kms: dynamically allocate power state space

We previously used a static array, but some new systems
had more states then we had array space, so dynamically
allocate space based on the number of states in the vbios.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=33851

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 4f29d44..56c48b6 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -812,8 +812,7 @@
 	fixed20_12		sclk;
 	fixed20_12		mclk;
 	fixed20_12		needed_bandwidth;
-	/* XXX: use a define for num power modes */
-	struct radeon_power_state power_state[8];
+	struct radeon_power_state *power_state;
 	/* number of valid power states */
 	int                     num_power_states;
 	int                     current_power_state_index;