drm/radeon/kms: add dpm support for rv6xx (v3)

This adds dpm support for rv6xx asics.  This includes:
- clockgating
- dynamic engine clock scaling
- dynamic memory clock scaling
- dynamic voltage scaling
- dynamic pcie gen1/gen2 switching

Set radeon.dpm=1 to enable.

v2: remove duplicate line
v3: fix thermal interrupt check noticed by Jerome

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index dbffeca..bcdefd1 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -116,6 +116,7 @@
 	/* Disable *all* interrupts */
 	for (i = 0; i < RADEON_NUM_RINGS; i++)
 		atomic_set(&rdev->irq.ring_int[i], 0);
+	rdev->irq.dpm_thermal = false;
 	for (i = 0; i < RADEON_MAX_HPD_PINS; i++)
 		rdev->irq.hpd[i] = false;
 	for (i = 0; i < RADEON_MAX_CRTCS; i++) {
@@ -163,6 +164,7 @@
 	/* Disable *all* interrupts */
 	for (i = 0; i < RADEON_NUM_RINGS; i++)
 		atomic_set(&rdev->irq.ring_int[i], 0);
+	rdev->irq.dpm_thermal = false;
 	for (i = 0; i < RADEON_MAX_HPD_PINS; i++)
 		rdev->irq.hpd[i] = false;
 	for (i = 0; i < RADEON_MAX_CRTCS; i++) {