drm/radeon: use frac fb div on DCE8

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -555,7 +555,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		if (rdev->family < CHIP_RV770)
 			radeon_crtc->pll_flags |= RADEON_PLL_PREFER_MINM_OVER_MAXP;
 		/* use frac fb div on APUs */
-		if (ASIC_IS_DCE41(rdev) || ASIC_IS_DCE61(rdev))
+		if (ASIC_IS_DCE41(rdev) || ASIC_IS_DCE61(rdev) || ASIC_IS_DCE8(rdev))
 			radeon_crtc->pll_flags |= RADEON_PLL_USE_FRAC_FB_DIV;
 		/* use frac fb div on RS780/RS880 */
 		if ((rdev->family == CHIP_RS780) || (rdev->family == CHIP_RS880))